Chairman Jon Kaiman chairs his final meeting of the Nassau...

Chairman Jon Kaiman chairs his final meeting of the Nassau Interim Finance Authority at the Long Island Marriott in Uniondale on Feb. 3, 2016. Kaiman is one of five Democrats running in the Third Congressional District. Credit: Newsday / J. Conrad Williams Jr.

Former Suffolk Legis. Jon Cooper endorsed former North Hempstead Supervisor Jon Kaiman for the Third Congressional District seat over Cooper’s former legislative colleague Steve Stern.

Cooper, who was the legislative majority leader, called Kaiman “the most progressive” candidate in the field of five Democrats seeking to replace retiring Rep. Steve Israel (D-Huntington).

“I think now more than ever we need someone who works for progressive ideas,” said Cooper. “Jon stands by his core values and does not hold his finger up to see which way the wind is blowing. I respect his consistency and willingness to take progressive stands even when it may not be the safest thing to do.”

Cooper said Kaiman is popular with people outside the Democratic Party and would be able to reach across the aisle to foster an “atmosphere of compromise.”

Stern campaign manager Joe Diver noted that Stern (D-Dix Hills) has been endorsed by Israel. Diver said Stern “has a proven, progressive record of fighting for our values. Stern has consistently fought to protect a women’s right to chose and clean up the Long Island Sound, and he’s the best choice to continue Rep. Steve Israel’s exceptional legacy.”

The district covers parts of Nassau, Suffolk and Queens. Kaiman said Cooper’s backing will help in Suffolk because Cooper is “someone who really has earned his stripes” and “really knows how government works,” which gives his endorsement credibility.