(Bloomberg) -- Up and down Wall Street and along Park Avenue, in the soft-carpeted corridors of moneyed Manhattan, few have embraced things Trump quite like the billionaire Stephen Schwarzman.For four years, the Blackstone Group Inc. chief executive officer has publicly stood by President Donald Trump even as many other corporate chieftains have pulled back. He has lent his name to a blue-ribbon committee, counseled the president during evening phone calls, helped shape tax law -- and thrown more money at Trump’s re-election campaign than anyone else in American finance.Now Schwarzman, 73, is acknowledging that Trump lost, and Joe Biden will be the next president. Schwarzman issued a statement on Monday saying he was ready to help the Biden administration.The Trump era has been wildly lucrative for pretty much anyone who’s been invested in markets. Schwarzman has seen his personal fortune roughly double to $20 billion. Big policy wins, especially around taxes, suggest that his fealty to a man he’s known since the 1980s has paid off for him and his industry. That support was still on display two weeks ago, when Schwarzman questioned some vote-counting totals as Trump embarked on an unprecedented effort to subvert the election.Yet with Trump’s term drawing to a close, Schwarzman’s star in Washington may begin to dim. Other leaders at the firm, Jon Gray and Tony James, are noted Democratic supporters who both hosted fundraisers for Biden this year -- suggesting that if any Blackstone executives are receiving calls from the Oval Office next year, it might not be the CEO.“Steve has offered advice to presidents of both parties over the last two decades with only one objective -- trying to help the country and reach positive outcomes for the American people,” company spokesman Matt Anderson said in an email. “He has never spoken to this president -- or any president -- on a Blackstone-specific issue. Any insinuation to the contrary is categorically false.”‘Move On’Schwarzman said in Monday’s statement that the outcome of the Nov. 3 vote was “very certain today and the country should move on.”“I supported President Trump and the strong economic path he built,” Schwarzman said. “Like many in the business community, I am ready to help President-elect Biden and his team as they confront the significant challenges of rebuilding our post-Covid economy.”Trump has been pushing back against Biden’s victory ever since news organizations projected that the former vice president had won the election. His efforts have included multiple lawsuits and calls for state legislators to ignore results that he has said are fraudulent without providing any evidence.Earlier this month the Financial Times quoted Schwarzman as questioning some vote-counting occurrences in Pennsylvania in the immediate aftermath of the election. People close to him said that his comments, made on a call with business leaders to discuss the poll results, were taken out of context and that he regretted repeating the Trump campaign’s suggestions of voting irregularities.“I’m a fan of good process. In my comments three days after the election, I was trying to be a voice of reason and express why it’s in the national interest to have all Americans believe the election is being resolved correctly,” Schwarzman said in Monday’s statement.Backing TrumpThe comments are notable because Schwarzman was such an outsize supporter of Trump relative to his Wall Street peers. An August analysis by Bloomberg found that the Blackstone chief had given Trump’s re-election campaign $3.7 million of the $4.8 million it had raised from the U.S. financial industry in the previous 18 months.He also provided practical assistance to the president. Schwarzman founded the CEO council that advised Trump early in his tenure. And he tried to keep the group going when its members wanted to disband following Trump’s refusal to unequivocally denounce white nationalists and neo-Nazis in Charlottesville, Virginia, in 2017. Trump dissolved the body before any final decision was made.Blackstone staff mostly shrugged off Schwarzman’s close ties to Trump, according to insiders. The belief was that his behavior was necessary to maintain a mutually beneficial relationship with the president, they say.And the ties go well beyond Trump to the broader Republican Party.Blackstone employees donated a total of $29.5 million to Republican candidates and political action committees in the 2020 cycle, according to a Bloomberg analysis, compared with just $5.2 million for Democratic efforts -- though more than $28 million of the former figure was Schwarzman personally.Blackstone’s in-house lobbying team, meanwhile, is led by Republican Wayne Berman, and the external lobbying firms it uses -- most notably Harbinger Strategies -- are Republican-leaning. Schwarzman himself meets with U.S. senators, mostly Republicans including Majority Leader Mitch McConnell, people with knowledge of the matter have said.Policy WinsIt’s a relationship that’s paid off. The Trump years -- which in 2017 and 2018 also saw Republicans control both chambers of Congress -- have been very good for the firm and Schwarzman personally.The December 2017 tax law kept the controversial carried interest loophole for investments of three years or longer -- a boon for private equity, and a rule change that Schwarzman personally backed, according to a person familiar with the matter.“The tax reform bill increased the personal tax rates of every senior Blackstone executive given the near-elimination” of the deduction for state and local taxes, said Anderson, the Blackstone spokesman.Another change in the law that boosted the industry was the cut in corporate tax rates to 21% from 35%. That paved the way for Blackstone and its peers to convert from partnerships to C-Corporations, meaning that investors such as mutual funds could now buy the companies’ shares. That in turn boosted their stock prices: Blackstone is up more than 30% since its conversion in mid-2019, outpacing the S&P 500’s roughly 20% gain.The total return for Blackstone’s stock, including reinvested dividends, topped 900% during the eight years of President Barack Obama’s administration, and an additional 150% so far under Trump, Anderson said.The moves in the Trump years, along with Blackstone’s thriving fortunes -- assets under management rose to $571 billion from $367 billion four years ago -- helped swell Schwarzman’s wealth to $20 billion, according to the Bloomberg Billionaires Index. On the day before Trump’s inauguration, he was worth $10.6 billion.There may be more to come even after Trump leaves office: a move by the Department of Labor earlier this year to allow private equity investments in 401(k) gives the industry access to potentially trillions of dollars in retirement funds.(Updates with Blackstone spokesman’s comments starting in sixth paragraph.)For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2020 Bloomberg L.P.