Donald Trump is set to give his big immigration speech later Wednedsay after an impromptu meeting with the president of Mexico. The press is looking forward to portraying whatever he says as a colossal flip-flop and his campaign's gyrations for the past week or so have definitely been confusing.

Trump may have more wiggle room on immigration than it first appears, however. Much has been made of his intermittently stated commitment to deport all 11 million or so illegal immigrants in the United States (many immigration hawks, including Trump himself, believe the number is much higher).

The constituency for mass deportation is smaller than advertised. Not does it not include pluralities and even majorities of Republican primary voters in states Trump won, at least insofar as the exit polls can determine. It doesn't really include leading immigration hawk Sen. Jeff Sessions, R-Ala., or the people who wrote the formal immigration position paper appearing on the Republican presidential nominee's campaign website.

The percentage of Republicans who favor deportation over legalization isn't trivial. Thirty-eight chose that option in New York, 41 percent in New Hampshire, 44 percent in South Carolina, 39 percent in Ohio, a state Trump lost (though he did beat the winner, John Kasich, among pro-deportation voters by 31 points).

Support for legalization also falls in many polls when it is tested against other enforcement options besides just deportation. This Rasmussen survey, for example, found broad support for comprehensive immigration reform but 66 percent of respondents wanted border security to come before legal status.

Not only do these nuances give Trump some flexibility to still oppose amnesty while moderating on the question of removals. So does the Democrats' current immigration positioning.

Gone are the days when the Obama administration once hyped record deportations (even if the numbers could be disputed). A couple executive orders later, both the president and Hillary Clinton almost exclusively favor deporting border crossers and illegal immigrants who commit other serious crimes.

Virtually everyone, including Trump, would deport criminal aliens first. But almost any more serious commitment to interior enforcement, making it more difficult to sustain an illegal presence in the United States and deporting some people for immigration violations alone, would put Trump to the right of Clinton and the status quo.

Wonkier immigration restrictionists have generally preferred a strategy called attrition through enforcement. While this would involve some deportations, limiting access to employment and curbing other incentives for illegal immigration were always more important.

After Mitt Romney floated it in during the 2012 presidential campaign, this was ridiculed as self-deportation, not least by Trump himself. But people returning home voluntarily is in many cases both more efficient and more humane than some other available alternatives.

Once the illegal immigrant population has been reduced to a more manageable number that would likely be dominated by the people with deepest roots in America — and once the message is clearly sent to future prospective entries that legalization is no sure thing — amnesty could then be considered.

Liberal immigration restrictionist writer Mickey Kaus and others have long recommended reversing the comprehensive immigration reformers' legalization first, enforcement later (sometimes legalization and enforcement simultaneously) bargain with enforcement first, legalization later.

The conventional wisdom was that advocates of this position were men (and women!) without a country. But maybe the 2016 immigration polling suggests rank-and-file border hawks might be open to it.

Finally, Trump's thrashing of Romney as a mean-spirited self-deporter went down the memory hole as he branded himself as being tougher on illegal immigration than anyone else and even flirted with Sessions' advocacy of lower immigration numbers overall (a majority position among Republicans).

This perhaps suggests that Trump's voters will tolerate more movement from him on immigration than is generally assumed and will trust him to secure the border nonetheless. That kind of confidence limited conservative opposition to Ronald Reagan's amnesty in 1986, the failure of which triggered the distrust that continues thirty years later.

That's the immigration crossroads Trump finds himself at now.