Senator Ted Cruz’s presidential run is premised in part on the idea that, by speaking to the “values” of evangelical voters, he can mobilize them in numbers not seen in a very long time. “Imagine instead millions of people of faith all across America coming out to the polls and voting our values,” Cruz said yesterday, adding that these voters had been “staying home.”

Cruz’s decision to announce his run at Liberty University is itself a sign that he hopes to assume the mantle of leading evangelical champion. And as Jon Ward puts it, Cruz’s announcement was “an attempt to lay down a marker with American evangelicals, to claim that he is their guy.”

So here’s something worth watching: How will the GOP primary debate over immigration reform, in particular, play among these voters?

One basic fact about immigration reform that continues to get lost in the noise is that evangelical Christians support it. Religion writer Sarah Posner recently reported on polling showing that a majority of evangelicals want Congress to pass immigration reform and support a path to citizenship. Evangelical leaders played a major (if largely ignored) role in the failed push for reform last year.

I don’t pretend to have any insights into what motivates evangelical voters. But listen to those who do: As evangelical writer Jim Wallis has put it, evangelical Christians have long pushed for reform on the grounds that the status quo is immoral, and that we should welcome the “biblical stranger” among us who is merely trying to find a better life. Wallis seems to be liberal, but Posner points out that many evangelical leaders have advocated for reform on the basis of “biblical imperatives” that require us to “seek justice for immigrants,” though it’s not clear whether that message explains why many rank and file evangelicals do support reform.

On immigration, Cruz has staked out one of the most aggressive rhetorical postures of any high-profile Republican. While he doesn’t flirt with nativism of the Steve King variety, his national renown rests in no small part on his nonstop railing against “amnesty.” He has made rolling back Obama’s executive action shielding DREAMers from deportation a “top priority” for years. He was at the forefront of efforts to use Homeland Security funding as leverage against Obama’s more recent actions expanding protection from deportation to the parents of children who are U.S. citizens and legal residents.

It’s true that opposing Obama’s executive actions is not necessarily the equivalent of opposing comprehensive reform. But Cruz opposed the DREAM Act, a legislative path to legalization for DREAMers, and he has rejected the idea that Republicans need to be for a comprehensive immigration overhaul. The GOP-aligned Wall Street Journal editorial page bluntly criticizes Cruz’s “hard-edged message against immigration.”

Meanwhile, Mike Huckabee — who knows a little something about appealing to evangelicals — discusses these issues in a decidedly different way from Cruz. Huckabee would certainly denounce Obama’s executive actions, but he also advocates for a path to citizenship for the DREAMers in moral terms, claiming it would be wrong to punish kids for the actions of their parents, and that we should strive to create a way for DREAMers to achieve full participation in American society. Rebecca Berg recently reported on an event where Huckabee made this case to Christian voters, challenging them not to vote for him if they disagreed with his moral convictions — and was applauded for it.

It’s unclear whether Huckabee will run for president. But it would be welcome if he challenged Cruz’s claim on evangelicals by making a morally nuanced case about the plight of illegal immigrants — one that evangelicals appear open to hearing. (Tellingly, Huckabee adviser Hogan Gidley says supporting citizenship might not be disqualifying among GOP primary voters.) Jeb Bush, too, has talked in a morally nuanced way about the plight of illegal immigrants and has even suggested they might have something positive to contribute to American society (though he converted to Catholicism long ago, and may not be the perfect messenger to deliver this message to evangelicals).

Look, maybe support for immigration reform is skin deep among evangelicals. Maybe Cruz can appeal to them by vowing to keep up the crusade against gay marriage until the end of time and, generally, staking out a more culturally confrontational position than any other candidate. Maybe it’s true, as many have insisted, that support for “amnesty” of any kind is lethal among GOP primary voters. But I hope that isn’t true, and it would be nice to see it put to the test. Cruz’s claim of a direct line to the hearts and minds of evangelicals — even as he stridently opposes “amnesty” — would be one place to start.