Mitt Romney is the heavy favorite to replace Orrin Hatch in the Senate. But he still has to win a Republican primary. And even in Utah, where Romney is treated as royalty, this means proving his conservative bona fides.

“For instance, I’m a deficit hawk,” Romney assured a group of Republican women on Monday. “That makes me more conservative than a lot of Republicans and a lot of Democrats. I’m also more of a hawk on immigration than even the president. My view was these DACA kids shouldn’t all be allowed to stay in the country legally.” He continued: “Now I will accept the president’s view on this, but for me, I draw the line and say, those who’ve come illegally should not be given a special path to citizenship.”

It’s tempting to treat this as simple pandering: another example of Mitt Romney saying whatever it takes to win support from conservative voters. This is, after all, the same Mitt Romney who embraced mandatory health coverage as governor of Massachusetts, before disavowing it on the campaign trail. And the same Romney whose vocal criticism of Donald Trump didn’t stop him from auditioning to be secretary of state. But far from opportunistic, Romney’s hard line against DACA recipients reflects one of his true, long-standing political commitments. On most issues, the former Massachusetts governor may have been unconvincing as a “severely conservative” Republican, but on immigration, he appears to be a sincere hawk.

Romney emphasized his opposition to “illegal immigration” during his 2008 campaign for the Republican presidential nomination. “As governor, I authorized the state police to enforce immigration laws. I opposed driver’s licenses and in-state tuition for illegal aliens,” he said in a campaign advertisement, contrasting his positions with those of “Hillary Clinton and the Democrats.” “As president, I’ll oppose amnesty, cut funding for sanctuary cities, and secure our borders,” Romney said.

This position placed Romney to the right of the Republican mainstream. But he was in line with the GOP base. While he would lose the nomination to John McCain—a moderate on immigration—this hard-line position would redound to Romney’s benefit during the 2012 Republican primary, when he faced a formidable opponent in then–Texas Gov. Rick Perry, who entered the race as the avatar for the Tea Party’s anti-Washington fervor of the moment. Romney was the front-runner, but he also had a record of moderation in Massachusetts, and Perry loomed as a serious threat to his right.

There was just one place where Romney could outflank him: immigration. And he did exactly that, blasting Perry’s support of in-state tuition for undocumented students at Texas colleges and accusing Perry of creating a “magnet” for illegal immigrants. “That shouldn’t be allowed,” said Romney. “It makes no sense at all.” This led Perry to the reply that would fatally weaken his candidacy. “If you say we should not educate children who come into our state … by no fault of their own, I don’t think you have a heart.”

By that standard, Romney was happy to be heartless. At a GOP debate in South Carolina, he announced his opposition to the DREAM Act that was then being considered by Congress. “I’ve indicated I would veto the DREAM Act if provisions included in that act say that people who were here illegally—if they go to school here long enough, if they get a degree here—then they can become permanent residents,” he said. “I think we have to follow the law and insist that those that have come here illegally return home and apply—get in line with everyone else.” Romney infamously declared he was for “self-deportation” during a Republican debate in Florida, advocating a strategy of attrition, in which the United States would make life so difficult that immigrants leave of their own volition.

Romney’s position on immigration was so right-wing that, in its post-election autopsy of his defeat, the Republican National Committee urged future nominees to reject his approach entirely, warning of electoral irrelevance if the Republican Party cannot attract votes from Hispanic and Asian American communities.

Of course, Donald Trump won the party’s nomination, and the White House, by doing just the opposite, attacking immigrants (and other minorities) in harsh, racist terms. And while most of the Republican Party still refrains from using Trump’s language, it is fully on board with the president’s draconian immigration policies. But Romney was there first, urging a similarly uncompromising approach on immigration, indulging nativist impulse among Republican voters.

Romney’s history on immigration is one reason why we should not treat Trump as an aberration from the Republican Party but the outgrowth—and perhaps the apotheosis—of forces that have driven Republican politics for at least a decade. Romney’s hostility to illegal immigration helped him win the Republican nomination. What’s more, he gave tacit approval to Donald Trump’s birtherism, even welcoming his endorsement in 2012. After he lost, Romney attributed Obama’s re-election to a promise of “gifts” to black people, women, and the “children of illegals.”

Romney holds sincere, conservative views on immigration, but he also helped give rise to the divisive politics that he now criticizes in Trump. Romney indulged the worst impulses of the Republican base, feeding it an appetizer of racial resentment and leaving it hungry for someone who could offer a feast.