Sen. Marco Rubio is pushing a bill that would protect states that penalize Israel boycotters, spurring a freshman congresswoman to question his loyalties.

On Monday, the Florida Republican decried the statement from Rep. Rashia Tlaib, D-Mich., as anti-Semitic.

“This ‘dual loyalty’ canard is a typical anti-Semitic line,” Rubio said on Twitter, quoting a tweet from the previous day by Tlaib, a Palestinian Arab American. “#BDS isn’t about freedom & equality, it’s about destroying #Israel.”

BDS stands for the Boycott, Divestment and Sanctions movement targeting Israel.

Tlaib in the earlier tweet had attacked a Senate bill initiated by Rubio and Sen. James Risch, R-Idaho, that incorporates four Middle East-related bills that languished in the last Congress. One of the measures protects states that pass anti-BDS bills, including those that ban work with contractors who boycott Israel, from lawsuits. Civil libertarians have decried the state laws as impinging on speech freedoms.

“They forgot what country they represent,” Tlaib said in her tweet. “This is the U.S. where boycotting is a right & part of our historical fight for freedom & equality.”

Tlaib was quoting a tweet by Sen. Bernie Sanders, I-Vt., that described Rubio’s bill as “absurd” at a time that the government is shut down over President Donald Trump’s refusal to advance funding bills as long as they do not include the more than $5 billion he is demanding for a border wall with Mexico.

Also weighing in on Tlaib’s tweet was the American Jewish Committee.

“Tell us more about dual loyalty, @RashidaTlaib,” AJC said in a tweet attached to a photo of the newly elected congresswoman draped in the PLO flag.