John Wisniewski Bernie Sanders

State Assemblyman John Wisniewski (D-Middlesex) cheers for Bernie Sanders at the Democratic National Convention in Philadelphia last year.

(Aristide Economopoulos | NJ Advance Media for NJ.com)

TRENTON -- A major financial backer of U.S. Sen. Bernie Sanders' presidential campaign is supporting Democrat John Wisniewski for New Jersey governor, even though Sanders has decided to hold off on an endorsement in the race.

National Nurses United, which ran a pro-Sanders super political action committee, announced Tuesday that it has endorsed Wisniewski, a veteran member of the state Assembly from Middlesex County who is running an underdog campaign for this year's Democratic gubernatorial nomination.

Wisniewski, who was the New Jersey chairman for Sanders' 2016 presidential campaign, has "stood for progressive principles while also being a true leader who puts the needs of New Jersey residents first," said Jean Ross, the group's co-president.

He has also "demonstrated a willingness to fight for the working families of New Jersey," said Esteban Ramirez-Orta, registered nurse from West New York and a member of the group."

Wisniewski is one of many Democrats running in the June primary for the party's nomination to succeed Republican Gov. Chris Christie. Political experts say the early favorite for the nod -- and the general election -- is Phil Murphy, a millionaire former banking executive and ex-U.S. ambassador to Germany.

Wisniewksi said Tuesday he's honored to have "earned the support of the union representing America's most trusted profession -- registered nurses."

"Together we will forge a progressive future for New Jersey that includes guaranteeing health care as a human right and enacting single-payer, universal healthcare," he added.

Wisniewski has positioned himself as a Sanders-like populist antidote to Murphy, touting himself as an "outsider" in Trenton, despite his 21 years in the Assembly.

But last Friday, Murphy's campaign announced the support of Sanders' son, Levi Sanders. And hours later, Bernie Sanders himself said that while he's "confident" that Wisniewski "would make an excellent governor for New Jersey," he has not endorsed anyone in the race.

Later in the day, Jeff Weaver, Sanders' presidential campaign manager, announced he was backing Wisniewski.

Brent Johnson may be reached at bjohnson@njadvancemedia.com. Follow him on Twitter @johnsb01. Find NJ.com Politics on Facebook.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant. Find NJ.com Politics on Facebook.