WASHINGTON – Former Starbucks CEO Howard Schultz got a chilly reception from Democrats on his potential White House bid as a third-party candidate.

Democratic presidential hopeful Julian Castro warned Sunday that an independent run by Schultz would mean President Trump winning reelection in 2020.

“I have a concern that, if he did run, that, essentially, it would provide Donald Trump with his best hope of getting reelected,” Castro, the former Housing and Urban Development Secretary, told CNN’s “State of the Union.”

Castro like other Democrats fear that Schultz, who has described himself as a lifelong Democrat, would siphon off enough votes from the Democratic nominee to leave Trump with the most votes.

“I don’t think that that would be in the best interest of our country,” Castro said. “We need new leadership. … I would suggest to Mr. Schultz to truly think about the negative impact that that might make.”

Schultz, a billionaire, is mulling a 2020 bid for president as an independent and spoke to CBS’ “60 Minutes” he’s already assembled a campaign team that can get him on the ballot in every county and in all 50 states.

“I am seriously thinking of running for president,” Schultz said. “I will run as a centrist independent, outside of the two-party system. We’re living at a most-fragile time, not only the fact that this president is not qualified to be the president, but the fact that both parties are consistently not doing what’s necessary on behalf of the American people and are engaged, every single day, in revenge politics.”

He positioned himself as an alternative to a failing two-party system.

“I want to see America win. I don’t care if you’re a Democrat, independent, libertarian, Republican,” Schultz said. “Bring me your ideas. And I will be an independent person, who will embrace those ideas. Because I am not, in any way, in bed with a party.”

Almost immediately, panic broke out among liberals that Schultz could play a spoiler, much like how — fairly or unfairly — Democrats blamed Ralph Nader for George W. Bush’s win against Al Gore in 2000 and Republicans faulted Ross Perot for hurting George H.W. Bush’s reelection bid in 1992 to Bill Clinton.

“There is zero appetite for this, and there is an urgent need for the Democratic candidate to win in 2020,” tweeted Sen. Brian Schatz (D-Hawaii.)

Former President Obama’s aides also blasted the idea.

“If Howard Schultz goes through with this half-baked idea, he will pose an existential threat to a Democrat in what will likely be 2020 race decided by a few votes in a handful of states,” tweeted Dan Pfeiffer, a former Obama adviser.

David Axelrod, another Obama alum, said the prospect of a Schultz presidential run is the “only good news” Trump got this week.

And even Democrats from Starbucks’ home state urged Schultz to back down.

The Washington state Democratic Party posted a picture of a Starbucks cup with a handwritten plea: “Don’t do it, Howard!”