President Trump leaves the White House on Saturday en route to New York for fundraisers. (Shawn Thew/European Pressphoto Agency)

NEW YORK — President Trump predicted Saturday that Democrats who voted against the Republican tax plan in the Senate would pay a price at the polls, as he touted what could soon become his first major legislative achievement.

Trump’s remarks came at a fundraiser in Manhattan benefiting his reelection campaign and the Republican National Committee, just hours after the early-morning 51-49 passage of the Senate bill, which still must be reconciled with a House plan before it is sent to Trump’s desk.

Trump told an audience of about 400 donors that he had received a phone call about 3 a.m. notifying him of the passage of “the largest tax cut in the history of our country.” (It is not the largest, as The Post's Fact Checker shows.)

Trump relayed that 51 of 52 Republicans in the Senate voted for the bill, just enough that Vice President Pence didn’t have to be called in to cast a tiebreaking vote. Sen. Bob Corker of Tennessee was the lone Republican no vote, expressing concern over the growing deficit. Corker is not seeking reelection after his term.

“We got no Democrat help, and I think that’s going to cost them in the election because they voted against tax cuts,” Trump said. “I don’t think politically it’s good to vote against tax cuts.”

Democrats have argued that the Republican action on taxes will be politically advantageous to Democrats because the plan does far more to help corporations and the wealthy than people in the working class, some of whom could see their taxes rise in coming years. Several recent polls showed that a majority of voters oppose the Republican efforts.

Trump also recounted how he urged his staff to refer to “tax cuts” rather than “tax reform” when pitching the legislation because the latter could lead people to believe their taxes are going up.

Trump spoke at the restaurant Cipriani on 42nd Street in Manhattan. It was the first of three events scheduled Saturday to benefit his campaign and the RNC.

At the top of his remarks, Trump praised Republican National Committee Chairwoman Ronna McDaniel, the former chairwoman of the Michigan Republican Party, for helping him carry her state, long a Democratic bastion in presidential elections.

“She was somebody that was up there working very hard, and everyone said, ‘You’re wasting your time. Republicans can’t win in Michigan,’” Trump said. “And all of a sudden those numbers came in that night, and they said Donald Trump wins Michigan. I said, ‘Who the hell was that girl up there?’ I said, ‘Who was the person, who was that woman that did the job?’”

As Trump’s motorcade arrived in Manhattan, hundreds of onlookers lined the streets, with many taking pictures. But there were also protesters, some chanting, “Lock him up!” Others carried signs, including “Tax cuts destroy energy” and “A package of bologna would make a better president.”