All eyes are on Alabama as voters head to the polls in a race that has thrown Republican Party divisions into the spotlight.

Sen. Luther Strange faces former Alabama Supreme Court Chief Justice Roy Moore in Tuesday’s special election primary runoff. Strange was appointed to the seat by disgraced Gov. Robert Bentley after former Sen. Jeff Sessions resigned to become attorney general. 

Strange has the backing of President Donald Trump and Senate Majority Leader Mitch McConnell. But Moore, a controversial judge who was twice removed from the bench, can count on the support of conservative leaders and a few of Trump’s former advisers. There is some concern among Republicans that a Moore victory could embolden other primary candidates to challenge sitting Republicans.

“That’s what we’ve seen happen before and I think that’s not an unreasonable assumption,” said Senate Majority Whip John Cornyn of Texas, a former chairman of the National Republican Senatorial Committee.

So how do Republicans prevent that from happening?

“By Sen. Strange winning,” Cornyn said.

2018 impact?

The problem for party leadership is that Strange is in real danger of losing. And emboldening primary opponents is exactly what some of Moore’s supporters want.

“He’s going to be an inspiration for the rest of the country, for other candidates across the country to rise up and take on their own swamp creatures in their own states,” former Alaska Gov. Sarah Palin, the 2008 vice presidential nominee, said at a Moore campaign rally Thursday.

Eric Beach, chairman of Great America PAC, which hosted the rally with Palin, said he hoped a Moore victory would make GOP leadership think twice about getting involved in primaries.

“When you outspend a candidate just to keep the good old network intact, and that candidate only wins by a little bit or loses, I think the establishment has to ask themselves a question: ‘Do we want to keep spending millions of dollars just to protect one of our own?’” Beach said.

But don’t expect leadership allies to back down.

“It would be hypocritical if it weren’t just simply funny,” Steven Law said of Beach’s suggestion that a Moore victory could discourage leadership allies from getting involved in primaries. Law is president of the Senate Leadership Fund, a super PAC aligned with McConnell that has been active in the Alabama race.

For Republicans, the danger of electing a nominee too extreme to win a general election is only too real.

They’re haunted by the ghosts of failed candidates past, such as Missouri Republican Todd Akin, who sparked controversy during his 2012 Senate race with comments referring to “legitimate rape.”

“There are a lot of people that think my opponent would be a Todd Akin, an anchor around the neck of the party for the next couple years,” Strange said of Moore in a recent interview with the Washington Examiner. “I have to say, knowing him, that’s probably a valid concern — it really is.”

GOP strategists do not want a repeat of primaries that resulted in candidates who lost winnable races in Delaware, Nevada and Colorado in 2010, and in Indiana and Missouri in 2012.

“This is not a new phenomenon for Republicans,” said GOP strategist Josh Holmes, a former chief of staff to McConnell. “It’s something that we have faced each and every cycle since 2010 and adopted a different business model as a result in 2014.”

The party started playing in GOP primaries and spending money on preferred candidates. That’s continued in Alabama, with NRSC staffers on the ground in the final days of the race. Former NRSC Executive Director Ward Baker is also advising the Senate Leadership Fund, Law said.

Strategists say GOP incumbents also realize they have to do the grunt work to stay in touch with their constituents to ward off primary challengers.

The Trump factor

But candidates and campaign strategists have a new factor to contend with in 2018: the president.

Three Things to Watch in Tuesday’s Race

“When you stand against President Trump, you are playing chicken with a Mack truck,” Law said. “He has an outsized influence on Republican primary voters.”

In Alabama, Law and Trump are on the same side behind Strange. But there is some concern that Trump could back primary challengers over incumbents in future races.

Trump, Law said, is the “most significant factor” in primaries, and groups like the Senate Leadership Fund have to adjust to the new environment.

“One of the ways we tried to navigate [that environment] was by highlighting issues and candidate statements that could conceivably impact his decision-making,” Law said.

In the Alabama race, the group highlighted GOP Rep. Mo Brooks’ past comments criticizing Trump. (Brooks failed to make the runoff after finishing third in the August primary.) The group also ran ads criticizing Moore for not fully supporting a southern border wall, one of Trump’s major campaign promises.

Trump knows his own reputation is on the line if Strange loses Tuesday.

“They’re going to say, Donald Trump, the president of the United States, was unable to pull his candidate across the line,” he said Friday at a Strange campaign rally in Huntsville, Alabama.

It’s not clear whether a Strange loss would cause Trump to hesitate over endorsing candidates in future. Only eight Senate Republicans are up for re-election in 2018, compared to 25 Democrats — 10 of whom are running in states that Trump won.

The president has signaled he could back primary challengers in Arizona and Nevada. Beach of Great America PAC said his group is also watching Tennessee and Mississippi, where they could potentially support GOP primary challengers.

Contested primaries could force the party to spend money in primaries when that money could be better used unseating Democrats, said former NRSC spokesman Brian Walsh.

But Alabama has shown that GOP leadership and its allies are willing to spend in primaries. Law estimated the Senate Leadership Fund will have spent just under $5 million on the Alabama runoff.

Not your average primary

Despite questions about the long-term implications of Tuesday’s election, some Republicans warned against drawing conclusions from one special election race more than a year before next year’s midterms.

But with outside money pouring in, Moore’s campaign has cast this race as one with a broader impact.

“They kind of gave us a strategy which was to make this race not just about two men running against each other, but about the entire Republican base running against the face of the D.C. establishment, which is Mitch McConnell,” Moore’s general consultant Brett Doster said.

Though Moore garnered support from various conservative leaders and former Trump advisers such as Steve Bannon, it is not a clear-cut case of the D.C. establishment versus the conservative base, given Trump’s backing of Strange. 

It’s also not clear if this race could launch Bannon as an influential force in primaries.

The former White House chief strategist is reportedly gearing up to take on other GOP lawmakers. However, he did not get involved in Alabama until after Moore won the August primary by 6 points, one Republican strategist said.

Moore is also a unique candidate compared to other primary challengers who could emerge in 2018.

He entered the race with high name recognition thanks to his stints as chief justice of the Alabama Supreme Court. He was first removed from the court for refusing to take down a Ten Commandments monument from a state building. His second ejection came after he ordered probate judges to not comply with the Supreme Court ruling that legalized gay marriage.

Moore has a passionate base of religious supporters, even after his controversial comments linking homosexuality to bestiality, and using racially charged language.

“Luther Strange’s supporters just see it as kind of a pragmatic exercise, going to vote, etc.,” said Doster, Moore’s consultant. “Judge Moore’s supporters see it as a religious experience and [something] they must do in this battle for the heart and soul of the party, and the heart and soul of the country.”

Even though Alabama’s special election might be unique, Moore’s outside supporters are hoping his victory could be the spark that leads to successful conservative challenges.

“We think this is going to be an igniter for other races across the country,” Beach of Great America PAC said.