Leave it to Donald Trump. In an interview last week with CNN, the Republican presidential candidate made explicit what even the staunchest anti-immigrant leaders of his party have avoided saying out loud: Let the mass deportation begin.

Trump said he would deport all undocumented immigrants and then let the “good ones” back into the United States under unspecified conditions. He didn’t explain how he would round up an estimated 11 million people and get them out of the country. (“It’s feasible if you know how to manage,” he said. “Politicians don’t know how to manage.”)

Trump is not treading on new policy ground here. He’s merely putting in plain language an idea that Republican restrictionists, such as Rep. Steve King of Iowa and Sen. Jeff Sessions of Alabama, have already supported. The Republican House has passed legislation to eliminate President Obama’s executive actions protecting undocumented immigrants from deportation.

And while Democrats and independents may not support Trump’s proposal, 63 percent of Republicans agree that the “main focus” of immigration policy should be “developing a plan for stopping the flow of illegal immigrants into the U.S. and for deporting those already here,” a July CNN poll showed.

Managing a mass deportation would require a “federal dragnet” capable of snaring all the undocumented immigrants in the U.S. over five years and would cost about $200 billion, according to the pro-immigration (and liberal) Center for American Progress – assuming that 20 percent of them would depart voluntarily once the effort got started.

The pro-immigration (and conservative) American Action Forum is less sanguine. It reported that a combination of forcible and voluntary deportation would cost $420 billion to $619 billion over 20 years. Meanwhile, real gross domestic product would decline by 5.7 percent, or almost $1.6 trillion.

Provided that most Americans become willing to see the economy shrink and to shoulder hundreds of billions in additional government spending, deportation policymakers could move on to the logistics of removal.

What other presidential candidates support mass deportation? How do they propose to address questions like these?

 Considering that about 3.5 million undocumented immigrants reside in the U.S. with at least one U.S. citizen child under age 18, what should happen to these children when their parents are sent across the border?

Removing millions of largely Hispanic residents will ruffle the sensitivities of some foreign nations and human rights groups; how should the United States handle the diplomatic fallout?

Some undocumented immigrants don’t just work in the United States; they also employ others. How should ownership of their enterprises be awarded? Or should the businesses simply be shut down and their employees dispersed?

Given that the typical undocumented immigrant has been in the U.S. for more than a decade, and that the flow of undocumented immigrants has declined significantly since the mid-2000s, are such intractable issues really worth trying to sort out?

If Trump or any other Republicans are serious about mass deportation, they should have a real conversation about it – about its budgetary costs, along with its economic, human and diplomatic costs. Lay out the details, and explain what it would take to accomplish.

Those who oppose investing hundreds of billions in a policy shift of this magnitude might want to take the opportunity to make their views clear, too.