Donald Trump’s contradictory signals on immigration have left it unclear how far he is retreating from his primary-season pledge to deport all undocumented immigrants.

But it is clear that any step back from his signature call for mass deportation in the policy speech he has scheduled for Wednesday in Arizona would represent a distinct break from the voters who provided the cornerstone of his winning coalition during the Republican nomination fight. In fact, Republicans who support deporting undocumented immigrants supplied Trump’s margin of victory in most of the key contests before he broke open the race in April.

Those voters were so critical to Trump’s success that key advisers to some of his rivals question whether he would have won the nomination if he had expressed then the position he’s floating now: providing legal status to at least some undocumented immigrants.

“That sort of stake in the sand, ‘I’m not only going to build a wall, I’m going to throw them all out,’ is what created that sense that he really is different, not politically correct, not establishment, screw everybody, I’m going to do what you want me to do,” said Whit Ayres, the pollster during the primaries for Marco Rubio. “I don’t think he could have generated the sort of juice he generated and the loyalty in the vote without it.”

During the GOP nomination race, exit polls in 20 states asked Republican primary voters whether “illegal immigrants working in the U.S.” should be “offered legal status” or “deported to [their] home country.” Mass deportation did not win majority support in most places: In every state except Alabama and Mississippi, less than half of those GOP primary voters said those in the U.S. illegally should be deported, according to results posted on the CNN website.

But the voters who supported deportation voted for Trump in such commanding numbers that they provided a majority of his votes in every state where the exit poll asked the question except New York and Wisconsin. The chart below tracks the share of Trump’s votes that came from voters who supported deportation. As it shows, in such key early contests as New Hampshire and South Carolina, Trump drew about three-fifths of his total support from voters who backed mass deportation.


Trump Voters Who Also Supported Deportation


If Trump did not consolidate such support from voters who backed deportation, the race might have unfolded very differently. In Trump’s critical early victories in South Carolina, Virginia, Georgia, Arkansas, Illinois, North Carolina, and Missouri, exit polls showed that he trailed behind either Ted Cruz or Rubio among the majority of voters who supported legal status for undocumented immigrants. In Michigan, Trump tied with John Kasich among those pro-legalization voters, and in New Hampshire and in Florida he won them by just a single percentage point. In Tennessee, he beat Rubio among voters who supported legal status by a slim four percentage points.

But Trump won all of those states, many of them comfortably, because he carried at least 52 percent among the minority of voters who backed deportation in Georgia, Illinois, North Carolina, Michigan, Missouri, and Florida, and only slightly less in New Hampshire (51 percent), Virginia and Tennessee (49 percent), South Carolina (47 percent), and Arkansas (43 percent).

The gap between Trump’s support among those who did and did not support deportation was often enormous. In New Hampshire, South Carolina, Virginia, and Illinois, his vote share among voters who backed deportation was more than double his performance among those who did not. In Florida, supporters of legal status for undocumented immigrants split almost evenly between Trump and Rubio while deportation backers gave the New Yorker a decisive 48-point edge over the home-state Senator.

“It’s as if the Democrats had nominated George Wallace.”

Ayres, the pollster for Rubio, says deporting all undocumented immigrants and opposing any legal status (the position Bush, Rubio, and Kasich all supported) was more important than Trump’s call for building a wall in differentiating him from the field.

“Walls in key places [along the border] was a part of the immigration reform bill so it was the deportation that separated him most dramatically,” Ayres said. “If he had had an immigration position like Jeb’s or Marco’s, he would have had a very difficult time generating the plurality that he generated.”

Stuart Stevens, the chief strategist for Mitt Romney in 2012 and a frequent Trump critic, takes a slightly different view. He agrees that the nominee’s appeal to the voters most uneasy about immigration and demographic change was key to his victory. But even without mass deportation, he believes Trump would have found another way to consolidate those voters.

“Trump’s entire campaign, primary and general, has been based on an appeal to an ugly strain of resentment: resentment toward immigrants, resentment toward those who practice a different religion, [who] aren’t white,” he wrote in an email. “It’s as if the Democrats had nominated George Wallace, though Wallace had more respect for governing and understood policy far better than Trump. Hate is Trump’s jet fuel. If it hadn't been immigration it would have been something else.”

The question now will be whether Trump will still have enough “jet fuel” to generate the turnout he’s counting on from culturally alienated white voters if, in fact, he definitively retreats from such a core promise of his primary campaign.