Yesterday, C-SPAN’s “Washington Journal” program hosted Maryland Senator Ben Cardin, the Democratic chairman of the Senate Foreign Relations Committee, to field questions on the newly-struck nuclear deal with Iran. But for one of the channel’s callers, the real question was about Cardin himself.

“Mr. Cardin looks like a regular white guy, nice guy, whatever, but in actuality he’s a Jewish white guy,” said the caller, who identified himself as a Democrat named Eric from Georgia. “If the public was informed of that by C-SPAN, I think they would take his comments differently.” The caller went on to dispute Cardin’s credibility on Iran, and as the Washington Post put it, “appeared to be questioning Cardin’s loyalty to the United States.”

Cardin is an Orthodox Jew, though unlike his former colleague Senator Joe Lieberman, he has not made his faith a major part of his public persona. Unsurprisingly, he took exception to the caller’s invocation of the classic anti-Semitic canard that Jews are more loyal to Israel than their home countries.

“I normally am pretty tolerant to people who ask questions, but I’m not to your assumption,” Cardin said. “I take great offense to that. Our loyalty is to America, our concerns are to America. Our religion is our own personal business and should have nothing to do with an evaluation by anyone as to our objectivity on issues concerning America.”

Watch the exchange below:

The incident brings to mind another involving Democratic presidential contender Bernie Sanders. Last month, on NPR’s Diane Rehm Show, the Vermont senator was asked about his Israeli citizenship—something he does not actually possess. Sanders took umbrage at the insinuation of dual loyalty, and Rehm subsequently apologized, explaining that she picked up the conspiratorial allegation from a Facebook post.

Related: NPR Journalist, Citing Anonymous ‘List,’ Tells Bernie Sanders He’s an Israeli Citizen, Too