In the summer of 2008, Senator Joe Manchin III of West Virginia traveled to a mansion in Dallas for a fund-raiser that attracted Republican and corporate donors who have supported his efforts to scale back President Biden's domestic agenda.
In September, Senator Sinema stopped by the same home to raise money for her campaign from a similar group of donors.
Ms. Sinema and Mr. Manchin have drawn fire from the left for their efforts to shrink and alter Mr. Biden's proposals, but they have won growing financial support from conservative-leaning donors and business executives in a striking display of how party affiliation can prove.
Ms. Sinema is gaining support from Wall Street and the right for her opposition to raising income tax rates. Mr. Manchin has attracted new Republican-leaning donors as he has fought against much of his own party to scale back the size of Mr. Biden's legislation and limit new social welfare components.
It is not unusual for well-heeled political activists and business interests to give money to different parties. Liz Cheney collected a few checks from major Democratic donors this year as she bucked her party leadership's defense of former President Donald J. Trump.
Many of the donors to the campaigns of Ms. Sinema and Mr. Manchin have little history with them. The financial support has been tied to their power over a single piece of legislation, the fate of which continues to rest largely with the two senators because their party cannot afford to lose either of their votes in the evenly divided Senate.
Their influence has been profound. The domestic policy bill, which would expand the social safety net and efforts to fight climate change, started out at $3.5 trillion and has been shrunk by Mr. Manchin to around $2 trillion as the Senate takes up the version passed on Friday The plan to pay for the new spending measures had to be substantially rewritten because of Ms. Sinema's opposition.
Kenneth G. Langone, a long-time Republican megadonor who has not previously contributed to Mr. Manchin, praised him for showing courage and promised to throw one of the biggest fund-raisers I have ever seen.
In a statement to The New York Times, Mr. Langone said that his political contributions have always been in support of candidates who are willing to stand tall on principle.
Stanley S. Hubbard, a billionaire Republican donor, wrote his first check to Ms. Sinema in September and said that he was considering doing the same for Mr. Manchin because of their efforts to trim the sails of the Democrats' agenda. He thinks we need more of those in the Democratic Party.
Cash has poured in for Mr. Manchin and Ms. Sinema from political action committees and donors linked to the finance and pharmaceutical industries, which opposed proposals initially included in the domestic policy bill that the lawmakers helped scale back, including changes to Medicare and the tax-rate increases.
John LaBombard, a spokesman for Ms. Sinema, said that there was no correlation between campaign cash and her approach to policymaking. She was one of the lead negotiators on the bipartisan infrastructure deal that Mr. Biden signed last week, and she has positioned herself as an ideologically flexible centrist willing to buck her party in representing a purple state.
Mr. LaBombard said that Senator Sinema makes decisions based on what's best for Arizona.
The office of Mr. Manchin did not respond to requests for comment. He's worried that the legislation would add to the budget deficit and cause inflation if it's not trimmed back.
The lawmakers share a campaign finance consultant who helped organize fund-raising swings through Texas for both of them that yielded cash from Republican donors, as well as a fund-raiser for Ms. Sinema in Washington in late September with business lobbying groups that oppose the domestic policy bill.
Nelson Peltz, a billionaire investor who brought a group of Republicans to have lunch with Mr. Manchin, said the senator understands that you can't spend, spend, spend and feel there's no recourse for it.
Mr. Peltz said that Ms. Sinema had requested a meeting, which will take place in a few weeks.
The two Democratic senators who are up for re-election in the next few years can use the donations of individual donors like Mr. Peltz, who has donated nearly three times as much to Republicans as he has to Democrats at the federal level.
Mr. Manchin has been to the right of his party on issues like abortion rights and fossil fuels, while Ms. Sinema started her political career as a liberal activist. One Wall Street executive joked that Ms. Sinema was now referred to as "Saint Sinema" for opposing most of Mr. Biden's proposed taxes on the wealthy. She supports a 15 percent corporate minimum tax and other revenue-raising measures that will help pay for Mr. Biden's legislative spending.
Progressives accuse both senators of being in cahoots with special interests to undermine their party's agenda.
The liberal group Demand Progress wrote in a petition that a small group of right-wing Democrats backed by corporate cash, including Joe Manchin and Kyrsten Sinema, are trying to oust Ms. Sinema in the primary in 2024.
Major Republican donors who had never before given to Mr. Manchin and Ms. Sinema include James A. Haslam III, who owns the Cleveland Browns football team, and the Dallas real estate developer.
Several prominent Republican donors wrote their first ever checks to Mr. Manchin. The lobbyist and investor Roy W. Bailey, the Oklahoma oil and gas billionaire Harold Hamm, and the bankers are included.
In the spring and summer, executives at Goldman gave tens of thousands of dollars to Ms. Sinema. In July, she attended a meet-and-greet at the offices of the Blackstone Group, which is headed by a major Republican donor. The chief executive of Apollo Global Management donated to Ms. Sinema after the firm sent a plea to industry contacts for donations.
The image is.
Mr. Manchin and Ms. Sinema were hosted by G. Brint Ryan at his Dallas mansion.
The Republican donor who hosted the fund-raisers in Dallas for Mr. Manchin and Ms. Sinema said the senators were out of step with their party but he believed they were in the right.
Mr. Ryan donated $1,000 to Mr. Manchin's re-election campaign, though he hadn't previously donated to either Ms. Sinema or Mr. Manchin.
The website for Mr. Ryan's tax consulting firm says it helps clients from being overtaxed.
Lobbyists for the firm have been watching the debate in Congress over the tax implications of the domestic policy bill. Mr. Ryan has ties to Republicans who helped lead opposition to the measure.
He was an advisor to Mr. Trump on tax policy. Jeff Miller is a partner in Mr. Ryan's tax consulting firm and is a lobbyist for Representative Kevin McCarthy of California.
Mr. Miller helped Mr. Ryan organize the fund-raisers for Ms. Sinema and Mr. Manchin. Ms. Sinema received a gift from Mr. Miller's wife.
Mr. Ryan, his employees, his company, and a relative's law firm all contributed to Ms. Sinema's campaign.
In the first nine months of this year, the $2.6 million raised by Ms. Sinema was two and a half times as much as the same period last year, while the $3.3 million raised by Mr. Manchin was more than 14 times as much.
In the first nine months of the year, Ms. Sinema's campaign took in $6.1 million in donations and had $4.5 million in the bank with three years to go until she faces the voters in Arizona. Mr. Manchin had $5.4 million on hand and raised about $3.8 million.
Kate Kelly reported from New York. Jonathan Weisman was involved in reporting.
