Donald Trump said he does not support same-day voter registration because he says it makes it easier for noncitizens to vote.

Because Trump complained repeatedly that the primary process was fixed, Meet the Press host Chuck Todd asked Trump if he supports policies that make it easier for people to vote. Same-day voter registration, for example, allows voters to register or update their information at the polls on Election Day.

"No, no," Trump said to the suggestion. "I don't think people should sneak in through the cracks. And whether that's an ID or any way you want to do it. But you have to be a citizen to vote."

"Well, of course," Todd replied. "That is the law as it stands already."

Trump disagreed: "No, it's not. I mean, you have places where people just walk in and vote."

In most states, people have to register to vote at least a few days prior to voting. But 15 states and the District of Columbia have or are in the process of implementing same-day voter registration. Is it really the case that noncitizens can just "walk in and vote" in these states?

Election experts told us there’s no increased risk of noncitizens voting in states with same-day registration, as opposed to states that require voters to register in advance, because of the safeguards the states put in place.

"It’s not that you can just show up and vote — you have to register and provide necessary ID," said Michael McDonald, a political science professor at the University of Florida.

To register someone to vote, states have to establish the voter’s identity and residency. To meet equivalent standards when registering people on Election Day, same-day registration states require the voter to bring proper identification and proof of residency, such as a utility bill, with them to the polls.

The specifics, though, vary by state because each state makes its own election laws. So if there are problems with ineligible voters using same-day registration, it likely has more to do with how the state implements the program, rather than a problem inherent to the general concept of same-day registration, said Barry Burden, a political science professor at the University of Wisconsin.

For example, some, but not all, states have an electronic database that they can use to check a same-day registrant’s eligibility on the spot. Others, like Iowa and New Hampshire, send a mailer to all same-day registrants, and if the card is returned as undeliverable, the state will investigate the case as potential election fraud.

But the bottom line is that states strive to hold everyone to the same level of scrutiny in terms of identity verification.

"For presidential elections, all states require voters to be U.S. citizens, and there is nothing inherent about same-day registration that would make it easier for noncitizens to vote," said Joshua Douglas, an election law professor at the University of Kentucky College of Law.

Douglas noted that some local jurisdictions do allow noncitizens to vote in certain elections, but it’s still illegal for them to vote in federal elections.

Every expert we asked told us that there are anecdotal examples of noncitizens voting in federal elections, but it’s rare. And there isn’t any evidence that it’s more prevalent in the states with Election Day registration.

For someone to vote fraudulently using same-day registration, they would have to lie about their eligibility in the presence of poll workers and others, and they would create a paper trail by filling out the paperwork. These factors serve as deterrents, in addition to the potentially severe penalties a fraudulent voter could face, like deportation if the person was in the country illegally.

Burden pointed to a recent case in Wisconsin of a man who has been charged with election fraud for voting in the state’s April 5 presidential primary. The man, who is not a citizen but is in the United States on a green card, registered and voted at the polls on Election Day. But the state government caught the man, and a spokesman for the Wisconsin Government Accountability Board told the local news that the agency had never encountered a similar case before, in 40 years of Election Day voter registration.

"For someone who’s not eligible to vote, to walk into a polling place and use same-day registration is risky," Burden said, noting that there’s a higher risk of election fraud in activities that occur outside the polling location, such as mail-in ballots.

Our ruling

"You have to be a citizen to vote," but with same-day voter registration, "you have places where people just walk in and vote."

In states with same-day voter registration, people don’t just walk in and vote. They have to provide the same level of identification as when registering in advance. Experts told us there is no additional risk of noncitizens casting ballots in states with same-day voter registration, nor is there any evidence that this occurs.

We rate Trump’s statement False.