Rand Paul didn't need to explain himself.

In May 2010, the small crowd assembled at a country club in Paul's hometown of Bowling Green, Ky., was already sold. Paul had just posted a commanding, unlikely victory in the Republican Senate primary in Kentucky, marking an important, legitimizing moment for the national Tea Party movement.

But on this night of triumph, Paul wanted to make sure that his audience of true believers understood that his platform was not on the fringe of American politics.

“The Tea Party message is not a radical message. It’s not an extreme message,” Paul said. “What is extreme is a $2 trillion deficit. That’s what’s extreme. The Tea Party message calls for things that are widely popular among Republicans, Democrats and Independents.”

Just look at the polls, Paul said. Most Americans support term limits or mandating that Congress balance the federal budget.

Paul was not challenging anyone to cross party lines to support him, but emphasizing post-partisan points of overlap. Harnessed though he was with the “Tea Party” label, Paul was speaking to the center.

As Paul now looks toward a potential bid for president in 2016, he is still struggling to shake the notion, held by many powerful Republicans and average Americans, that he is outside the political mainstream. The word “transformative” is thrown around regularly by Paul's allies as they envision what shape his presidential bid could take: Paul doesn't have to change, the subtext reads; it is the Republican Party that must evolve and expand to accommodate his vision.

Indeed, Paul’s policies seem to cater to a yet-emerging idea of the American political center, which was outlined in great detail in an Esquire-NBC News survey last year. The poll was remarkable because, rather than relying on party identification to classify voters, it assigned them to one of eight groups of like-minded Americans across the political spectrum based on policy preferences, with four of the eight groups comprising the center.

The poll showed that most Americans identify most closely with Democrats on some important policy preferences, such as social issues, but simultaneously gravitate toward some Republican economic policies. They want the U.S. to be a strong international superpower, but largely disengaged. And yes, they support term limits.

Last year, in an interview with New York Magazine, Paul's 2010 Senate primary opponent, Trey Grayson, tried to rationalize how Paul was able to at once be uncompromising and attractive on policy.

“One thing that Rand is able to do is to persuade people,” Grayson said. “In our race, if he was going to give you an answer you weren’t going to like, he would give it to you in a way that wouldn’t offend you. It might even make sense to you. And you might even end up thinking that he agreed with you.”

The challenge for Paul at this stage, however, is not to persuade the American public of his policy correctness or his electability. Paul’s immediate target audience is an invisible primary electorate made up of influential party donors and power brokers, many of whom are relatively unfamiliar with Paul or wary of his political brand.

The process has involved relentlessly courting allies outside the traditional Libertarian core of support built up by his father, Ron Paul -- such as Rupert Murdoch, who accompanied Paul to this year's running of the Kentucky Derby.

But to land such meetings, Paul's political reputation alone does not always suffice, often requiring an assist from allies more connected to the mainstream Republican Party, such as Senate Minority Leader Mitch McConnell.

“You think Rupert Murdoch would have come to the Kentucky Derby with Rand if McConnell hadn't told him what a good guy he is?” said one Republican source with knowledge of the meeting. Indeed, since Paul has actively supported McConnell in his challenging re-election bid, McConnell has in return acted as an emissary of sorts for Paul with mainstream donors and party influencers. Then, once Paul gets in the room, his allies say, he’s gifted at closing the deal.

“When McConnell puts his arm on Rand's shoulder, he goes from a curiosity to a serious player,” the party source explained. “McConnell helps open the door, and Rand charges in.”

Also opening doors for Paul is Nate Morris, 33, a Kentucky-based businessman and former bundler for George W. Bush's 2004 presidential campaign, who boasts deep connections in the business community and a close friendship with Bush's former finance guru, Jack Oliver. Morris each month has been helping to set up several introductions between Paul and deep-pocketed GOP influencers.

Just as the Republican establishment has been slow to warm to Paul, support from the religious right — an important constituency in a Republican presidential primary — has also been somewhat elusive.

Paul began working to shore up support among religious conservatives with a trip to Israel early last year. The trip was the brainchild of David Lane, an evangelical activist with deep ties in Iowa, who has been at the center of Paul's efforts to appeal to the religious right. Also along for the ride were A.J. Spiker, the former Iowa Republican Party chairman who in March stepped down to steer Paul's PAC; now-former South Carolina GOP Chairman Chad Connelly; Mallory Factor, who holds influential meetings among conservative power brokers in New York and South Carolina; and Morris, among others.

But Paul has attracted the most notice for reaching far beyond the traditional Republican base of support — with a speech at Howard University in Washington, a historically black college, and by reaching out to black pastors.

“I haven't seen this kind of inclusive thinking since George W. Bush,” said one Republican familiar with Paul’s strategy. “He’s going places where Republicans typically won't go.”

But Paul’s inclination to throw political caution to the wind also makes him a pronounced wild card — and unnerves many Republicans. For every issue on which he attacks Democrats and the president, there is another on which he’ll gladly skewer his own party.

During the 2010 Senate race, for example, Paul’s campaign website attacked George W. Bush-era congressional Republicans for lowering taxes without cutting back on government spending.

“Republicans have been much more vocal than Democrats in their support of low taxes and reduced spending,” the site read. “However, while lowering taxes, they dramatically increased federal spending, doubling the national debt during the last administration. They were unable to balance the budget a single year they were in charge under the previous administration. Getting only half of the equation right just isn't good enough.”

Part of Paul's broader appeal, though, and one ingredient in the special sauce his team believes could propel him to the White House, is that Paul has never hewed to arbitrary Republican best practices or political correctness. When Paul announced he was forming an exploratory committee to run for Senate in Kentucky, he decided to do so not on Fox News, or on a conservative talk radio show, but in an interview with MSNBC's Rachel Maddow.

"Rand's not exactly a stick-your-finger-in-the-air kind of guy,” said Jesse Benton, McConnell’s campaign manager, who formerly ran Paul’s Senate campaign and remains entrenched in Paul’s innermost circle.

On the night of his Senate primary victory in 2010, Paul was feeling some of the same pressures he is now to sand down the sharp corners of his political persona.

“People are already saying, now you need to weave and dodge,” Paul said. “Now you need to switch. Now you need to give up your conservative message. You need to become a moderate. You need to give up the Tea Party. You need to distance yourself.”

The audience erupted in a cascading chorus of, “No!” Paul, in agreement with the crowd, shook his head.