New York City Mayor Bill de Blasio had strong words for former South Bend, Indiana, Mayor Pete Buttigieg, who finished a distant third in the Nevada caucuses on Saturday: “Try to not be so smug when you just got your ass kicked.”

With 23% of precincts reporting, Sen. Bernie Sanders (I-VT) had won 40.3%, leading former Vice President Joe Biden with 22.0% and Buttigieg with 17.0% — barely above the 15% threshold for winning delegates to the national convention.

Buttigieg, delivering a speech to supporters, congratulated Sanders, but warned that he was too radical to win a national election.

He said:

Before we rush to nominate Senator Sanders in our one shot to take on this president, let us take a sober look for what is at stake for our party, for our values, and for those with the most to lose. There is so much on the line. And one thing we know for sure is that we absolutely must defeat Donald Trump and everything that he represents in November. [Cheers, Applause] This is important. We share these ideals. but I believe the best way to defeat Donald Trump and deliver for the American people is to broaden and galvanize the majority that supports us on the critical issues. Senator Sanders believes in an inflexible, ideological revolution that leaves out most Democrats, not to mention most Americans.

De Blasio, who was once a candidate himself but has since endorsed Sanders, mocked the South Bend mayor on Twitter in response:

.@PeteButtigieg, you clearly don’t understand the movement @BernieSanders has built. It reflects the true values + hope of working people in America. They simply want a country that puts working people first. Your critique tonight speaks for the American elite, not the majority — Bill de Blasio (@BilldeBlasio) February 23, 2020

And hey @PeteButtigieg, try to not be so smug when you just got your ass kicked. You know how we form a winning coalition to beat Trump? With a true multi-racial coalition of working Americans: something @BernieSanders has proven he can do + you haven’t. Dude, show some humility — Bill de Blasio (@BilldeBlasio) February 23, 2020

Tensions have flared between the Sanders and Buttigieg campaign ever since Buttigieg declared victory prematurely in the Iowa caucuses, as an actual count of votes was delayed by a malfunctioning app. Sanders won the popular vote in Iowa and appeared to have tied, or nearly tied, Buttigieg in the race for “state delegate equivalents” after a re-canvas of some of the disputed caucus sites.

Notably, De Blasio backed Sanders over his own predecessor as mayor, Michael Bloomberg.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He earned an A.B. in Social Studies and Environmental Science and Public Policy from Harvard College, and a J.D. from Harvard Law School. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. He is also the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.