From left, White House chief strategist Stephen K. Bannon, senior adviser to President Trump Kellyanne Conway, deputy national security adviser K.T. McFarland and then-national security adviser Michael Flynn on Feb. 8. (Jabin Botsford/The Washington Post)

As President Trump scrambled to fill his vacant national security adviser slot following Michael Flynn’s resignation earlier this month, one name kept popping up in news reports: K.T. McFarland.

McFarland was tapped to serve as deputy national security adviser in November. She had served in previous administrations, including those of Richard Nixon, Gerald Ford and Ronald Reagan, and earned Trump’s trust, perhaps in part by virtue of appearing on Fox News with regularity. When Robert Harward turned down Trump’s offer to replace Flynn, one of the reported reasons was that he wanted to boot McFarland from her position. Trump had indicated to her that she could keep her position, however, and lacking assurances that he could pick his own staff (as well as for other reasons), Harward passed.

There is one detail from McFarland’s past that might give Trump pause, though, based on his recent statements: About 15 years ago, she appears to have violated New York state laws pertaining to voter registration.

Trump’s failure to win the popular vote in November has led him to embrace and advocate baseless conspiracy theories about voter fraud. At first, Trump broadly argued that millions of illegal votes had been cast, a claim that’s devoid of any actual evidence. Eventually, he modified that claim somewhat, conflating illegal votes — ballots cast illegally — with out-of-date voter registration information. Before Election Day, he warned of millions of dead people who were still registered to vote, a function of election boards being slow to update voter rolls. He used this same argument in his Super Bowl interview with Fox News’ Bill O’Reilly.

“When you look at the registration and you see dead people that have voted, when you see people that are registered in two states that voted in two states, when you see other things,” Trump told O’Reilly, “when you see illegals, people that are not citizens, and they’re on the registration rolls. Look, Bill, we can be babies, but you take a look at the registration, you have illegals, you have dead people, you have this. It’s really a bad situation. It’s really bad.”

In 2006, McFarland flirted with the idea of running for Senate in her home state of New York. The New York Post looked at her voting history, reporting:

McFarland, a Reagan administration official in the early 1980s, has maintained two voting addresses since 1996: at her posh Park Avenue home and at her family’s stunning second home on a small island near Southampton, according to the records.

She pingponged her vote from Manhattan to Southampton in various years, casting her ballot from the Ram Island address in 1998 and 1999, but voting from Park Avenue in 2000 and 2001.

She skipped the 2002 and 2003 elections, and then it was back to voting in Southampton in 2004, according to the records.

State law makes it a felony to be registered at two addresses during the same election cycle, according to state Board of Elections spokesman Lee Daghlian.

This is slightly different than what Trump presented as being a “bad situation.” There’s no indication, for example, that McFarland voted twice in the same election in two different places. But McFarland’s lawyer conceded to The Washington Post that she’d violated the law, blaming election officials: “She should have been turned away.”

She is by no means the first member of the Trump administration or family to have dual registration issues. Reporting from The Post indicates that a daughter, Tiffany Trump, Treasury Secretary Steve Mnuchin, son-in-law Jared Kushner, press secretary Sean Spicer and senior adviser Stephen K. Bannon were registered to vote in multiple states. This is not illegal in most cases — in part because it’s a natural side effect of people moving between states. (It’s uncommon for people to judiciously and proactively inform their previous states of residence to cancel their registrations.) Trump cites these millions of dual-registered voters as a hint that millions of illegal votes may have been cast, but there’s literally no evidence that this is the case.

McFarland never faced charges for her dual registration. Had she cast votes in both places, the result might have been different. She is currently registered to vote at Ram Island.

The voter registration question was one reason that she ended up losing the Republican primary that year. Another was that she claimed that the Democratic incumbent was using helicopters to fly over her house and take pictures.

That Democratic incumbent, of course, was the same person Trump accused of being the beneficiary of widespread, multiple-voter fraud: Hillary Clinton.