HOMEWOOD, Ala. — Republican voters are fed up.

More than eight months into President Trump's administration, with the government under full GOP control, there's no southern border wall, tax reform hasn't happened, and perhaps most infuriating, the effort to repeal and replace Obamacare has stalled yet again, for lack of Republican support.

That smoldering resentment sparked a brushfire of angry voters in Alabama.

In a late September special election to determine permanent ownership of the Senate seat formerly held by U.S. Attorney General Jeff Sessions, upstart conservative Roy Moore, former chief justice of the state supreme court, defeated appointed Sen. Luther Strange, whose sins were the fact that he was an incumbent, and he was supported by Senate Majority Leader Mitch McConnell, R-Ky.

"I am sick — up to here — with these do-nothing Republicans," said Johnny Creel, 56, who runs a small insurance agency in suburban Birmingham, just down the road from Strange's neighborhood. "I love the judge because he doesn't back down. Luther has jumped in to bed with Mitch McConnell."

Moore won easily, despite being massively outspent by McConnell and his allies in Washington, ceding just four of 67 counties to Strange. He is the heavy favorite to win the seat outright in a December special general election against Democrat Doug Jones. Even Trump's endorsement couldn't save Strange.

Now the disgust that led to Strange's ouster threatens to engulf Republicans up and down the ballot for next year's mid-terms.

Conservative populists who fueled Moore's upset victory included activists and VIPs such as Steve Bannon, Trump's former chief strategist who leads Breitbart News, along with the mega-wealthy Mercer family. They're buoyant from their success, and they're on a search-and-destroy mission for Republicans elsewhere in the country.

If the GOP Congress can't manage to deliver the marquee items they promised in 2016, the insurgents are likely to find a receptive audience of GOP voters in midterm primaries. David Winston, a Republican pollster who advises the congressional leadership, said the environment could take an even worse turn if the GOP doesn't start producing.

"Now that healthcare hasn't happened, it raises the stakes for tax reform. It's a big deal," Winston said. "If that doesn't happen, where there aren't points on the board that Republicans need, let's not just think about the primaries, we're talking about [problems] in the general election."

Jordan Gehrke, a Republican strategist who usually works for conservative primary challengers and has experience harnessing the frustrations of the GOP base for outsider candidates, agreed. (His brother, Joel Gehrke, is a reporter at the Washington Examiner.)

Gehrke advised third-place finisher Rep. Mo Brooks, who is a member of the House Freedom Caucus targeted for defeat by McConnell, in round one of Alabama's special GOP primary, and he warned that the runoff is a harbinger of what awaits Republican incumbents next year.

It's still avoidable. But competing factions have to achieve consensus on big-ticket items in Congress and send them to Trump's desk for signing. More specifically, centrists such as Sen. Susan Collins, R-Maine, and libertarians such as Sen. Rand Paul, R-Ky., need to find a way to agree on repealing Obamacare.

"Republican voters are incredibly angry right now," Gehrke said. "They don't understand how it is that they can have all three branches of government, and yet it hasn't gotten done — Obamacare's the biggest promise that's been broken."

Frustration on the Right has been building for nearly a decade.

Republican voters chaffed under the leadership of President Barack Obama as he and a Democratic Congress pushed liberal priorities such as the Affordable Care Act. Winning control of the House in the 2010 Tea Party wave did nothing to assuage them.

In fact, it almost made matters worse for Republicans in Congress by empowering the populist Right and raising expectations for what the GOP House could accomplish with a Democratic Senate and Obama in the White House. Winning the Senate with nine pickups in 2014 had the same effect: Raised expectations that Republicans weren't able to satisfy.

Having Trump in the White House hasn't been the panacea to the Republicans' governing challenges. The president is a divisive figure who hasn't proven an able negotiator of legislative deals or a unifier of the party's conservative and centrist wings.

He periodically hops on Twitter to beat up his allies on Capitol Hill, stoking mistrust between Congress and the White House and further poisoning voters' opinion of the legislative branch. The result has been a dysfunctional majority mired in infighting, just like when Obama was president.

"This is not just a rejection of quote-unquote establishment," argued Josh Holmes, McConnell's former chief of staff and the architect of his victories in competitive primary and general election campaigns in 2014. "This is a response to a very divisive internal relationship within the Republican Party that has led to a stagnant agenda."

Except that's not how Republican voters see it, and they're the ones holding the cards in 2018.

In their telling, they grudgingly accepted Republican leaders' admonitions throughout the Obama years that conservative change wasn't possible without the White House, even as they picked off the House and then the Senate.

Now, with Trump in office, the voters aren't willing to entertain any more excuses. Indeed, they're quite satisfied with the president's handling of his job, his attacks on Republicans in Congress especially.

"He's trying to honor his promises," said Mark Locket, a retiree from Mobile, Ala., who preferred Sen. Ted Cruz, R-Texas, in the 2016 primary but has come around to Trump. "He hasn't been terribly effective so far. But then again he hasn't had much support from his own party."

Lockett, of course, voted for Moore.

With the victory in Alabama under their belt, conservative agitators, from Bannon and Breitbart News, to the Senate Conservatives Fund, led by Ken Cuccinelli, the former Virginia attorney general, to anti-establishment media figures such as Fox News' Laura Ingraham, are looking for more scalps.

And it's not so much about ideology as opportunity. Strange supported Trump more than 90 percent of the time; he supported the latest Obamacare repeal bill Trump wanted the Senate to pass, while Moore said he would have opposed it if he had a vote.

But with Moore's uniquely loyal and expansive following in Alabama, he was the perfect proxy to take on McConnell and the established order in Congress, who ultimately was transformed into something of a bogeyman in this race, similar to how House Republicans were able to effectively use House Minority Leader Nancy Pelosi, D-Calif., against Democratic candidates running in special House elections this year.

Michael Rinker, 47, who lives about an hour east of Birmingham, largely blamed McConnell for his decision to back Moore. And Rinker isn't even one of Trump's biggest fans. He wrote in Sen. Marco Rubio, R-Fla., on his 2016 presidential ballot. "My biggest complaint is, Mitch McConnell's spending a lot of money in this race."

That's why senior Republican strategists are begging incumbents in safe red states, including Sens. John Barrasso, R-Wyo., Deb Fischer, R-Neb., and Roger Wicker, R-Miss., to prepare early for a primary that could be a lot more formidable now that the activists and donors who fund conservative challengers believe that their investments might pay off.

That's if what happened in Alabama doesn't chase them out of the Senate first. Sen. Bob Corker, R-Tenn., was girding for upheaval in his 2018 primary until he decided not to seek re-election, announcing his retirement the same day that Strange fell to Moore.

"The dominant presence of Trump and the unpopularity of Congress among primary voters will continue to influence primary elections in 2018 and beyond, and will require effective strategies to deal with them," Steve Law, who runs McConnell's super PAC, which spent $9 million on Strange, wrote in a memo to donors.