Donald Trump wants to immediately deport 2 million to 3 million undocumented immigrants with criminal records. One problem: There almost certainly aren’t that many people who fit those criteria.

In a “60 Minutes” interview that aired Sunday, Trump said he would prioritize deporting or incarcerating the immigrants who are both in the country illegally and who are “gang members, drug dealers” or have other criminal convictions. He said there are “a lot of these people, probably 2 million, it could be even 3 million.”

It isn’t clear where Trump came up with those numbers. But according to the Department of Homeland Security, there are roughly 1.9 million non-citizen immigrants who have been convicted of crimes and are subject to deportation — what the government calls “removable criminal aliens.” That total, however, includes both undocumented immigrants and noncitizens in the country legally. The Migration Policy Institute, a think tank, estimates that there are roughly 11 million immigrants in the U.S. illegally and that approximately 820,000 of them have criminal records. (The Migration Policy Institute doesn’t take positions on specific legislation but is generally seen as favoring immigration. The Pew Research Center, another think tank, comes up with a similar figure for the total number of undocumented immigrants.) Some of those immigrants are already incarcerated: A recent report from the Congressional Research Service estimated that at the end of 2013, there were more than 140,000 non-citizen immigrants in local, state and federal prisons and jails. (That figure includes people who are in the country legally, not all of whom are subject to deportation.)

Beyond the specific numbers, the policy that Trump outlined Sunday is similar to the one President Obama pursued in his first term. When Obama first took office, he prioritized deporting undocumented immigrants with criminal convictions, in some cases even for comparatively minor violations such as traffic offenses or shoplifting, according to Randy Capps of the Migration Policy Institute. Partly as a result, deportations soared under Obama, topping 400,000 in 2012.

More recently, however, the Obama administration has changed tack, focusing instead on deporting immigrants convicted of more serious crimes or for repeat offenses. (He has also consistently deported undocumented immigrants who entered the country recently.) Deportations have fallen steadily in Obama’s second term, to below 250,000 in 2015.

Capps said that the Homeland Security Department still has the resources it had in Obama’s first term. From a practical standpoint, then, it wouldn’t be hard for the government to deport 400,000 or even 500,000 people per year — meaning that Trump could credibly deport 2 million people during his first term without requiring additional resources or authorization from Congress. Many, but not all, of the people deported would be convicted criminals.

“It would not be hard to get up to 2 million in four years, and most of them would be quote-unquote criminals,” Capps said, although he added that many of those criminal convictions would be for relatively minor crimes.

Trump is also likely to roll back a central element of Obama’s immigration agenda: his Deferred Action for Childhood Arrivals program, which offers temporary legal status to people who entered the country illegally as children. During the campaign, Trump pledged to end DACA, but he hasn’t said how — whether he will close the program to new applicants, allow it to expire or end it even for the roughly three-quarters of a million people who have been granted legal status under the program.

“The proof is going to be in what his administration actually does,” Capps said, “and it will take some time before we know that.”