Minnesota Sen. Al Franken on Sunday said a newly-released Donald Trump campaign advertisement had an “Elders of Zion feel to it.” The two-minute ad, dubbed Trump’s “argument for America,” has been largely criticized as anti-Semitic due to the inclusion of billionaire George Soros, Federal Reserve Chair Janet Yellin, and Goldman Sachs CEO Lloyd Blankfein—who are all Jewish—with camera shots of Wall Street and Washington, D.C.

“When I saw the ad, I thought that this was something of a German shepherd whistle, a dog whistle, to a certain group in the United States,” Franken said on CNN’s “State of the Union.” “I’m Jewish, so maybe I’m sensitive to it, but it clearly had sort of Elders of Zion feel to it.”

The Protocols of the Elders of Zion was a fabricated book published in 1903 that linked Jews to a plot to take over the world.

Franken added that the ad was likely a play to Trump’s “alt-right base,” and is “an appeal to some of the worst elements in our country.” The ad was also condemned by the Anti-Defamation League, which said it peddles “painful stereotypes and baseless conspiracy theories.”

—Andrew Desiderio