Already feeling overwhelmed by the 2016 presidential race? It's understandable with 16 major Republican candidates running for White House. This doesn't count a slew of lesser-known aspirants, including some former governors who would merit attention in a smaller field.

People ridiculed the 1988 Democratic presidential candidates as the "Seven Dwarves." So far, no one has called this group the Sweet 16. Only 10 at a time are expected to appear together onstage for debates sanctioned by the Republican National Committee. Among them are senators, governors, a successful businesswoman, a retired neurosurgeon and author and a billionaire reality TV star.

Can any of them beat Hillary Clinton? They have reason to hope, for the last time Clinton looked inevitable, she lost. Her odds of making it out of the Democratic primaries are much better this time. So far, she has attracted four challengers and only Bernie Sanders, the socialist senator from Vermont, has attracted a meaningful following. Neither Joe Biden nor any other Democratic savior has emerged.

The general election is a shakier proposition for Clinton. She fares well in national polls, frequently beating her Republican rivals by double digits in hypothetical match-ups. But swing state polls tell a different story. In late July, Quinnipiac found her losing Colorado, Iowa and Virginia — they are all states Barack Obama carried twice and George W. Bush won at least once — to the leading Republican candidates.

But if the polls more than a year before the election were determinative, Rudy Giuliani and Richard Gephardt would have been major-party presidential nominees, and John McCain might have been president of the United States. At this point, Clinton looks like a competitive but beatable candidate in the general election. But before any of the Republicans can beat Hillary, they must first defeat the rest of the GOP field.

The Republican race is wide open, with barely 10 points separating first and fourth places in the national RealClearPolitics polling average. Fewer than 20 points separate first place from fifteenth place, a spot occupied in July by a candidate with 0 percent of the vote.

Superficially, the 2016 GOP contest looks a lot like past races. You have an establishment candidate in Jeb Bush. The combined finances of his campaign and super PAC mean Bush is awash in money. He has a good team, solid organization and plenty of endorsements. Then there's a group of candidates competing to be the conservative alternative to Jeb.

Yet the race is, in other ways, like no other in recent memory. Bush is the establishment candidate, yes, but he is not the clear front-runner. He's led in only one major poll in Iowa since May 2014, and after trailing Mike Huckabee in an outlier poll in February, he has at different times lost his national lead to Scott Walker, Marco Rubio and, most recently, Donald Trump.

As with 2012, when Mitt Romney was the establishment candidate who was weak by historical standards, there has been a revolving door of candidates who seemed poised to claim the mantle of conservative challenger. Walker defied the odds and media stereotypes by giving a forceful presentation at a Republican cattle call in Iowa early in the year, receiving fulsome praise from Rush Limbaugh.

"If you have spent any time listening to this program in the last two years, you know I believe that Scott Walker is the blueprint for the Republican Party if they are serious about beating the Left," proclaimed Limbaugh, who remains an important opinion leader among grassroots conservatives. Thus Walker became the first conservative to give Bush a run for his (considerable) money.

Next there was Rubio, who got the biggest bounce out of his campaign launch of any of the Republicans. If a GOP consultant tried to design a presidential candidate for the party in a lab, the result would probably look like the junior senator from Florida: relatively young, telegenic, eloquent, capable of sharing the conservative message in a way that is accessible to voters outside the GOP base, Hispanic and from a crucial swing state.

If there was a candidate the Republican consultant would probably most want to avoid designing lest his creation turn on him and wreck the GOP laboratory, it would be Trump: super-rich and boastful about it; boorish and opinionated; insensitive and insulting to Latinos and other groups Republicans are trying to woo; no prior political experience. And yet it didn't take long for him for win plurality support in polls of Republican primary voters. Trump has already made this primary fight unlike any other.

These three men illustrate the unsettled nature of the race. Each moved rapidly from single-digit support to out-polling Jeb Bush in the wake of some major event that focused attention on their campaigns. The last two national polls taken before Trump announced his candidacy, for example, had him at 1 and 2 percent.

Rounding out the upper-tier conservatives are Ben Carson, the African-American former director of pediatric neurosurgery at Johns Hopkins University who has clearly captured the imagination of conservative Christian activists; Rand Paul, the Kentucky senator who is leader of the party's libertarian wing; Ted Cruz, the Tea Party senator from Texas whose $14.2 million opening fundraising haul should remind everyone not to write him off; and Mike Huckabee, the former Arkansas governor who galvanized evangelicals during his 2008 campaign.

Candidates such as former Texas Gov. Rick Perry, former Pennsylvania Sen. Rick Santorum, Louisiana Gov. Bobby Jindal and former Hewlett-Packard CEO Carly Fiorina are among the conservatives still on the outside looking in, waiting for an opportunity to move ahead just as New Jersey Gov. Chris Christie and Ohio Gov. John Kasich would like to displace Bush as the establishment favorite.

In April, the Washington Post quoted a New Hampshire man at a town hall meeting telling Bush that he didn't want to see a coronation on the Republican side like the Democrats appear to be having with Clinton. Bush laughed. "I don't see any coronation coming my way, trust me," he replied. "Come on. What do you see that I'm not seeing? We've got 95 people possibly running for president. I'm really intimidating a whole bunch of folks, aren't I?"

Bush likely hoped he could raise an intimidating amount of money early and muscle other Republican candidates out of the race, rather as his brother consolidated support early in 1999 and kept other top-tier contenders from jumping in. Jeb succeeded at the former, pulling in an impressive $114 million between his campaign and super PAC in the first quarter, but failed to keep anybody besides Mitt Romney from running.

Now Bush's path to the nomination seems to be to stay relevant through the first four state contests, maybe even win one or two of them, and engage Rubio mano-a-mano in Florida. If he wins Florida, he'll gain momentum. From there, he can out-spend and out-hustle his rivals, racking up wins in big states and vacuuming up delegates. There's no guarantee, since Rubio's underlying favorability numbers among Republicans and especially conservative activists are much higher. Bush is also in no position to attack Rubio's biggest weakness with conservatives, which is his dalliance with the Gang of Eight on immigration.

A Florida strategy is risky for Bush and even riskier for Rubio. Giuliani discovered when he tried it in 2008 that if you don't win any of the earlier states, by the time Florida rolls around, the race may have passed you by. Giuliani led more consistently and by bigger margins the year before the primaries than Bush ever has.

If nobody else is active in Florida, at least Bush or Rubio will be virtually guaranteed a win there. (Even after betting all his chips on the Sunshine State, Giuliani finished only third.) But if Rubio doesn't score a win before Florida, it's possible someone else will have already become the favorite conservative. Even a decisive win in South Carolina wasn't enough by itself to secure that status for Newt Gingrich in 2012.

Walker is the most obvious person to block Rubio's path. Like Rubio, he has one foot in the Tea Party camp and the other in the establishment camp. The Wisconsin governor is running as someone who is more principled than other election-winning Republicans, yet has more to show for his battles than the Tea Partiers who fight but lose.

Walker's path is narrow, however. If he wins the Iowa caucuses, he'll steal Rubio's thunder and give Bush a movement conservative opponent who could conceivably win the general election. He could parlay that into strong performances, perhaps outright victories, in New Hampshire and South Carolina, making any Rubio Florida strategy untenable. But if he loses Iowa, it becomes hard to construct a series of events that easily delivers him the nomination.

"I really thought Rand Paul would be in a different place by now," a Republican consultant said. But marrying more traditional Republicans to his father Ron Paul's libertarian base has proved more difficult than expected, especially after the Islamic State and Iran have raised the salience of foreign policy in the GOP primaries. Paul shouldn't be counted out, however. He has plans to compete in caucus states, the Interior West and blue states, which aren't usually on the map for candidates running to the right of the top establishment contender.

In order to do that, Paul probably needs to notch a win in at least one of the first four states. If he is riding high close to when the votes count — Ron Paul didn't start advancing in the polls until late in 2011 — Iowa, New Hampshire and Nevada look like rich targets, though South Carolina would be a stretch. The key is to keep competing with Walker, Rubio and Cruz for conservatives while still taking moderates from Bush. That will be very hard to do.

Cruz is more exciting than Walker, blunter than Rubio, and tells the conservative base fewer things they don't want to hear than Paul. If he were to win Iowa or South Carolina, it would likely help Bush to overcome conservative trepidation by pressing the electability argument. Bush can beat Hillary, he'll say, and Cruz can't. Cruz has to hope the party faithful doesn't want to hear it.

Christie probably needs Jeb to implode and an unelectable conservative to surge. Perry has run a much better campaign the second time around, but is still haunted by the collapse of his first presidential run. He can cite the best economic statistics for the state he governed, but will primary voters listen?

"I know [Carson] says some outlandish things," a Republican said. "But he's a brilliant man and may be just what this country needs." That's the kind of organic support Carson has attracted since criticizing Obama to his face at the National Prayer Breakfast. He could break any of the other conservative candidates, but it is hard to see him putting together the kind of organization it would take to compete in many states simultaneously.

That's how it goes for most of the rest of the Republicans running, who will be lucky to break into the debates. Fiorina has done the most to elevate herself as a public figure since announcing her candidacy. She's a media-savvy Hillary critic, and Republicans would like to see more of her. Santorum is once again banking on Iowa, as Jindal touts polls showing his rise in the Hawkeye State.

Trump is the GOP's big fear. Will he win the nomination and lose to Hillary? Will he disrupt the debates? Will he hurt the party's brand by staying in it or ruin Republicans' chances of winning the presidency by bolting to a third-party or independent candidacy? He seems self-absorbed enough to do either.

But his initial spike in popularity belies some limitations in his appeal, especially among dedicated party activists. "Trump attracts considerably more backlash than most other candidates, joining Bush, Graham and New Jersey Gov. Chris Christie among the candidates that more than 1 in 4 activists say they'd never vote for and that they'd be angry to see nominated," wrote Huffington Post's Mark Blumenthal and Ariel Edwards-Levy about a poll they did with YouGov, a British-based market research firm.

Blumenthal confirmed to the Washington Examiner that they used a rigorous definition of "party activist": registered Republican voters who had sought or held office, served as a party official, worked for an elected officeholder or done some combination of donating, volunteering and rally attendance. And these people didn't think Trump was likely to win the nomination or the presidency.

So there are many Republican candidates, each with different paths forward. But in the end, their campaigns describe only a few paths that can lead them to victory over Clinton. Bush clearly believes he can broaden the party's appeal to Latinos and white suburban moderates with tolerant rhetoric, outreach and a welcoming immigration platform.

Republican voters who dislike Bush tend to do so because of ideology, which can be turned into an advantage in the general election, or because they dislike the idea of a political dynasty, a problem that will plague him in the fall campaign even running against a former first lady.

Rubio hopes he can persuade voters that he has all Bush's positives without the dynastic negatives, and generates more enthusiasm among conservatives. He's also not been shy about using Clinton's age and association with even older Democratic symbols — she rebooted her 2016 campaign at Roosevelt Island, for example — as lines of attack.

Like jujitsu, this uses two things that would normally be Clinton advantages against her. First, Democrats love to nominate youthful candidates and portray Republicans as living in the past, even when they are relatively young, like Dan Quayle in 1988. Second, Clinton will want to appeal to the era of peace and prosperity of the 1990s, when her husband was president. The song that the Clintons were using to appear young and hip in 1992, Fleetwood Mac's "Don't Stop," was released when Rubio was six years old.

That could backfire. Voters may decide they liked the 1990s just fine. A party that nominated septuagenarians to run against Bill Clinton and Barack Obama might be willing to take the risk.

Paul hopes to soften the Tea Party's rough edges without moderating his conservatism but by using libertarianism to rebrand conservatism. His emphasis on criminal justice reform may win over groups that don't usually vote Republican. He hopes to do better with younger voters. And while he has a tougher path to the nomination, polls do show him competing well with Clinton in general election match-ups.

Walker may be left with a modified version of the Cruz strategy: turn out the base, like George W. Bush and Karl Rove did in 2004, and beat the Democrats in a war of attrition. Walker would try to add to this by outperforming recent Republican tickets in the Midwest and certain battleground states. Carrying Wisconsin is probably asking a lot, though he won't write it off after winning three elections there in four years. But what about Ohio or Colorado, or moving eastward to Pennsylvania?

When a Republican faces Hillary, the top-line economic numbers should be better than when Romney ran against Obama (how voters feel about their personal finances may be a different story). But the economy was much better the last time an incumbent Democrat tried to hand off the White House to another member of his party. That incumbent president, Bill Clinton, was more popular than Obama is now.

Al Gore still only managed to fight George W. Bush to a draw, and he ultimately lost. If "Clinton fatigue" was a real thing in 2000, and it was, Obama fatigue is likely to be worse in 2016. That doesn't favor Hillary, a candidate who has both her husband's low ratings for personal honesty and Gore's lack of people skills.

Republicans have to hope they can counteract the demographic advantages Democrats have enjoyed in the last two presidential elections, and that women don't get anywhere near as excited about the prospect of the first female president as many Americans did about the first black president. They don't have a lot of margin for error. But they do have options, both in terms of which candidate they will nominate and which approach they will take to defeat Hillary.