What is Mike Pence thinking? That’s what many conservatives began to wonder last week when it became clear that the Trump campaign is seriously considering the Indiana governor as a potential vice-presidential nominee, and that Pence in turn is seriously entertaining the prospect of joining the Trump ticket.

Several Pence allies say that he will accept the nomination if it is offered to him. Coming as it does from the man who led the principled conservative opposition to George W. Bush in Congress; who has long claimed to be “a Christian, a conservative, and a Republican, in that order”; and whom the New York Times in 2006 dubbed “the perfect conservative,” the willingness to embrace Trump has come as a surprise to many.

It’s clear what Pence would bring to the Trump ticket. Trump has performed strongest among moderates, in particular with self-identified Republicans who are nonetheless registered Democrats, and choosing Pence would send a signal to anxious conservatives that the GOP nominee isn’t hell-bent on alienating them. Pence has both congressional and executive experience, and as a low-key policy wonk, he would strike different note on the campaign trail.

It’s more difficult to figure out what would be in it for Pence. Several of the governor’s confidants spoke on the condition of anonymity, agreeing to shed light on what could be the most significant decision of his political career. In many cases, they asked not to be quoted directly. Their accounts paint a portrait of a devoutly religious man paying close attention to how he can best serve the country, but also of a battered governor who believes a spot on the national ticket could simultaneously lift him out of a tough reelection campaign in Indiana and make him a top prospect for the Republican nomination in 2020 or 2024.

“He would obviously be a favorite for a future presidential campaign after Trump has been president, and that’s unusual for somebody who didn’t run himself in what was a very crowded and talented field this year,” says Kellyanne Conway, the Trump pollster and longtime Pence consultant who brought the Indiana governor to Trump’s attention as a potential vice-presidential nominee.

Pence eschewed entreaties from conservatives to run for president in 2012 and again in 2016, but those close to him say he’s always had his eye on the White House. He first ran for Congress, unsuccessfully, in 1988, when he was just 29 years old, and, after a brief stint as a successful talk-radio host, began climbing the political ladder in earnest.

As a politician, Pence has been far more successful on the federal level than in his own state.

As a politician, he has been far more successful on the federal level than in his own state. In Congress, he rose to national renown as a staunch opponent of the Bush administration’s domestic initiatives from No Child Left Behind to Medicare Part D and finally to the bank bailouts of 2008. He rose steadily through the GOP ranks, becoming chairman of the Republican Study Committee in 2005 and GOP conference chairman in 2009. But messy fights over a state-funded pre-kindergarten program and a religious-liberty law have marred his tenure back in Indiana, where he was elected to the governorship in 2012.

Pence’s allies say he was deeply shaken by the backlash to his decision last March to sign the Religious Freedom Restoration Act into law, which cast a pall over his administration. He did so in the face of fierce opposition from Indiana’s business community, led by the Indiana Chamber of Commerce. Pence had campaigned for governor on a platform that highlighted jobs and education. A lengthy Indianapolis Monthly profile published shortly before he was sworn in as governor detailed how he intentionally downplayed his record as an outspoken social conservative while campaigning for governor; the passage of the RFRA allowed Pence’s adversaries to portray him as the Bible-thumper they had always claimed he was.

Conway calls it Pence’s baptism by fire. “This was his near-death political experience,” she says. “It was no longer the mano-a-mano conversation between conservative, evangelical Christians and LGBT-rights advocates. With the business getting involved they created asymmetrical warfare,” she says. Indeed, the Indianapolis Star ran a front-page editorial about the law calling on Pence to “fix this now.” The hashtag #boycottindiana began trending on Facebook. And his approval ratings plummeted 15 points in the year after he signed the bill, according to a Ball State survey, even as he hired a public-relations firm to help him deal with the mess.

The result is that the governor, having given the most grudging of endorsements to Ted Cruz in the primaries earlier this year, is now locked in a close reelection race at a time when few are celebrating the Republican brand with which he is so closely associated.

Enter Trump, who carried Indiana’s May 3 primary by 17 points. Trump is scheduled to campaign in the state on Tuesday alongside Pence, who by all accounts found the GOP nominee utterly charming during their tête-à-tête last weekend in New Jersey.

The governor’s allies say universally that he views his budding relationship with Trump through the lens of a call to service. “He’ll approach it as, where does he feel called to serve?” says one longtime Pence friend. And he believes his knowledge of and reverence for the Constitution, as well as of the inner-workings of Capitol Hill, can supplement Trump’s obvious shortcomings. “I think he would view this as an opportunity . . . basically to add value by saying, ‘This is what the president does and doesn’t do, and here’s what you need to do to move a bill in Congress.’”

The governor’s allies say universally that he views his budding relationship with Trump through the lens of a call to service.

Though Pence relished public, partisan combat during his time in Congress, he rarely veered from his staunch conservatism, once boasting that he was a tea partier before the Tea Party was cool. He is a devout Evangelical Catholic with the social-conservative record to match. And on immigration, he has favored something of a compromise position, arguing that illegal immigrants should return to their home countries and then enter the United States legally.

All of this of course situates him far from Trump on the ideological spectrum, but his allies say he nonetheless considers Trump preferable to the Democratic nominee, Hillary Clinton.

“I think his calculation would be that ‘Hillary Clinton would be a terrible choice for president and if there’s something I could do to prevent that, well, I’ll do it,’” says the longtime friend.

Then there are the other uncomfortable realities: Trump is a popular figure in Indiana, and Pence is in a tough race that the vice-presidential nomination could remove him from. He’ll have to know by Friday, which is the deadline for him to pull his name from the ballot for Indiana governor, since state law prohibits candidates from running for both offices at the same time.

Nobody questions Pence’s conservative bona fides. What he may have learned from his tenure as governor, and from the battle over the RFRA in particular, is that standing on principle isn’t always sufficient, that ideological compromise and brass knuckles are sometimes necessary to move the ball forward.

If Trump 2016 led ultimately to a Pence nomination in 2020 or 2024, many conservatives would be delighted.

— Eliana Johnson is the Washington editor of National Review.