Breitbart columnist David Horowitz labeled conservative figurehead Bill Kristol a “Renegade Jew” for his push to keep presumptive GOP nominee Donald Trump out of the White House.

Horowitz, who is Jewish, published a column on Sunday titled “Bill Kristol: Republican Spoiler, Renegade Jew Prepares Third Party Effort to block Trump’s Path to White House.” Within hours, the phrase “Renegade Jew” was trending on Twitter.

The column picked apart the Weekly Standard editor’s plan, laid out in a weekend op-ed, to “recruit and support an independent candidate” who could keep both Trump or Democratic frontrunner Hillary Clinton from winning the election.

Only the last paragraph touched on faith. Horowitz charged that by opposing Trump, Kristol allied himself with Clinton and proponents of the Iran nuclear deal, thus strengthening countries that endanger Israel and weakening “the only party that stands between the Jews and their annihilation”:

I am a Jew who has never been to Israel and has never been a Zionist in the sense of believing that Jews can rid themselves of Jew hatred by having their own nation state. But half of world Jewry now lives in Israel, and the enemies whom Obama and Hillary have empowered — Iran, the Muslim Brotherhood, Hezbollah, ISIS, and Hamas — have openly sworn to exterminate the Jews. I am also an American (and an American first), whose country is threatened with destruction by the same enemies. To weaken the only party that stands between the Jews and their annihilation, and between America and the forces intent on destroying her, is a political miscalculation so great and a betrayal so profound as to not be easily forgiven.

For his part, Kristol told The Daily Beast’s Tim Mak that he had no intention of reading the column:

Bill Kristol on Breitbart story calling him a “renegade Jew”: “I haven’t read it, and can’t say I intend to.” — Tim Mak (@timkmak) May 16, 2016

Other Twitter users either mocked or condemned the label Horowitz chose for Kristol.

Only “renegade Jews” don’t back an authoritarian who won’t take moral sides with Israel and flirts with the Nazi-cheering alt-right and KKK. — Ben Shapiro (@benshapiro) May 16, 2016

“Renegade Jew” is foretaste of the really anti-Semitic stabbed-in-the-back myths we’ll see when Trump loses in fall pic.twitter.com/vpgU1a1uax — Jeet Heer (@HeerJeet) May 16, 2016

I was more into Renegade Jew’s early work. — Matthew Yglesias (@mattyglesias) May 16, 2016