Vice President JD Vance said at a Michigan campaign rally that Democrat Senate candidate Abdul El-Sayed lied about being an immigrant from another continent, pointing to the candidate’s past statements about his own origins.

Vance, stumping for Republican nominee Mike Rogers, told the crowd that El-Sayed had misrepresented where he came from, according to video posted by the Trump War Room. The vice president framed the race as a test of national loyalty.

“We have to understand what happens when our nation gives in to these kinds of people, to young men with zero attachment to its land or to its history, with a man who would lie, who is so ashamed of this state that he would lie about being an immigrant from another continent,” Vance said.

El-Sayed was born in Michigan in 1984 to Egyptian immigrants. At the Michigan Democratic Party’s 2017 convention, he told the party’s Progressive Caucus he “may be an immigrant from North Africa,” according to video obtained by the Washington Free Beacon. He listed U.S. and Egyptian citizenship on a 2014 Columbia University résumé and stated onstage at a 2016 Detroit conference that he held “dual citizenship.”

El-Sayed’s campaign has denied he ever held Egyptian citizenship. Spokeswoman Roxie Richner told the Free Beacon the candidate was misinformed by a relative and called the claim “an error based on what he was told by family members secondhand.” Richner said El-Sayed “is not a dual citizen by any verifiable metric and never has been.”

Responding to Vance at an earlier stop, El-Sayed described himself as “a Wolverine, not a weasel” who was born and raised in the state, and his campaign has said Republicans lift his past comments out of context.

The exchange comes as Vance campaigns for Rogers, whose toss-up race against El-Sayed could determine Senate control. Vance told supporters at an earlier Monroe rally that El-Sayed is “one of the craziest, one of the most far-left, and one of the most radical people running for high office in the history of the United States of America.”