Donald Trump is getting fundraising assistance from some of the Republican party’s top financiers (Ricky Carioti/The Washington Post)

Donald Trump spent much of the Republican presidential primary contest inveighing against politicians for leaning on wealthy contributors for support. Now he’s doing the same.

On Tuesday, some of the GOP’s best-connected fundraisers signed on to help raise as much as $1 billion for Trump and the Republican National Committee, part of an effort to rapidly build out a finance operation that the candidate has lacked until now.

Half a dozen of the party’s elite money players — including New York Jets owner Woody Johnson and Wisconsin billionaire Diane Hendricks — have agreed to serve as vice chairs of the Trump Victory fund, a joint fundraising committee between Trump’s campaign, the RNC and 11 state parties, the party announced Tuesday.

Johnson served as finance chairman for former Florida governor Jeb Bush’s presidential bid, while Hendricks donated $5 million to a super PAC supporting Wisconsin Gov. Scott Walker.

Corey Lewandowski, Trump’s campaign manager, said that the candidate was not contradicting his stance on rich donors by accepting their help, noting that most of the money raised would go to the RNC for its national voter mobilization this fall.

“That will benefit not only Mr. Trump, but all the races down ballot,” he said, adding: “I don’t think it’s fair to say that an individual worth $10 billion will be indebted to someone who writes a check for $10 or $100.”

In fact, the victory fund is seeking donations in far greater amounts. The first fundraiser, which Trump was set to headline Tuesday in Albuquerque, requires a $10,000 donation per person. Tickets for a high-priced dinner in Los Angeles on Wednesday at the home of investor Thomas Barrack Jr. start at $25,000.

And a rich supporter who wants to give more could shell out as much as $449,400 to the joint committee, whose proceeds are split between the Trump campaign and the party.

Leading the effort to bring in big dollars are major financial backers of Trump’s past rivals — even some he targeted as special interests who seek to control the agenda of the politicians they support.

Earlier this year, Trump regularly cited Johnson, an heir to the Johnson & Johnson pharmaceutical fortune, as someone who would influence Bush’s health-care and pharmaceutical policies.

Nevertheless, his comments did not rankle the New York Jets owner, who has been friends with Trump for three decades, according to a person familiar with Johnson’s views. Among the ties between the two men: Their daughters went to school together.

That kind of long-standing relationship that Trump has with wealthy business leaders has helped convert apprehension about the real estate developer into active support, donors said. The coalescing among the party’s money class has been accelerated by antipathy to Democratic front-runner Hillary Clinton.

“It’s the party unifying because they realize that Mrs. Clinton is not a viable choice,” said Ron Weiser, who was a national co-chair for Sen. John McCain’s 2008 presidential campaign and is one of the new Trump Victory vice chairs. “I think you’re starting to see that across the board.”

Just a few months ago, Florida developer Mel Sembler expressed dismay at the thought of Trump as the party’s nominee. “I kept telling myself that won’t happen, that can’t happen. . . . I now fear it may happen,” he told the Tampa Bay Times in February.

Now Sembler, who helped lead fundraising for a pro-Bush super PAC, has agreed to serve as a vice chairman of the victory fund.

When asked why, Sembler responded in a text message: “Trump will be the Republican Party’s nominee.”

As a sign of party unity, the past three RNC finance chairmen have come aboard the effort: Weiser, a former ambassador to Slovakia; Dallas investor Ray Washburne, who had been the national finance chairman for New Jersey Gov. Chris Christie; and Los Angeles venture capitalist Elliott Broidy, who serves on the board of the Republican Jewish Coalition.

“There is truly a sense that we’re going to win this thing, that Trump can win it,” Washburne said. “Everyone is going to throw their shoulders behind it and put money behind it.”

The operation is being led by Lew Eisenberg, the RNC’s finance chairman, and is getting a big boost from experienced finance staff at the party headquarters. Chairman Reince Priebus is even calling major fundraisers himself, asking them to host events.

The firepower reflects anxiety among senior GOP fundraisers about meeting Trump’s declared goal of $1 billion — a sum that would require the committee to pull in an average of $250 million a month during the next five months.

“If everybody does their job, anything is possible,” Weiser said. “But that’s a lot of hard money.”

The team is finalizing a schedule of fundraisers and is recruiting state finance chairs in each state.

An effort to actively solicit small donations online is also expected to kick off soon. That could provide a major infusion of cash for Trump’s campaign, which could tap into the kind of online fundraising juggernaut that has helped power the bid of Sen. Bernie Sanders of Vermont, Clinton’s Democratic challenger.

“There’s a real opportunity with the enthusiasm that people have for Donald Trump,” said Henry Barbour, a Mississippi-based GOP strategist who serves as a RNC national committeeman. “I think we’re going to find a lot of new low-dollar donors.”