Tucker Carlson, the far-right podcaster who left the Republican Party this year over opposition to the war with Iran, has taken to defending Dr. Abdul El-Sayed, the Democratic nominee in a pivotal Michigan Senate race. The unlikely alliance stems from shared opposition to the Israeli government and the war with Iran.

Mr. Carlson has repeatedly praised Dr. El-Sayed while castigating his Republican opponent, former Representative Mike Rogers, calling him the "embodiment of the cruelty and stupidity of the national security state" and saying he wouldn't vote for him "at gunpoint."

When Mr. Rogers targeted Dr. El-Sayed for saying U.S. military actions after Sept. 11 had "scarred millions," Mr. Carlson defended him, writing that Dr. El-Sayed "is obviously right." Mr. Carlson told The New York Times he doesn't make endorsements but continued attacking Mr. Rogers as "a toady to Israel and an enemy of civil liberties."

Political consultants view the dynamic as a "horseshoe alliance," reflecting how both ends of the spectrum align on certain issues. Josh Pasek, a professor at the University of Michigan, called it more likely a "marriage of convenience" than evidence the far left and far right share beliefs.