MediaNews Group/Torrance Daily Breeze via Getty Images via Getty Images A protester holds up a sign as presidential candidate Mike Bloomberg speaks at a campaign rally in Compton, California, on Feb. 3.

When Rep. Harley Rouda became one of the first members of Congress to endorse Mike Bloomberg for president, the California Democrat billed it as a marriage of moderates.

“He has been a fiscal conservative and a social progressive, which is where I believe most Americans are,” Rouda said. “That’s exactly what I ran on.”

But Rouda has another reason to feel an affinity for the 77-year-old billionaire. In the 2018 midterms, when Rouda was locked in one of the most contested elections in the country, Bloomberg spent $4.5 million of his vast personal fortune on ads thrumming Rouda’s Republican opponent.

Now, Rouda is in Congress — and one of three members who endorsed Bloomberg after a super PAC financed by Bloomberg spent millions of dollars to help elect them, records reviewed by HuffPost show.

Rep. Mikie Sherrill of New Jersey and Rep. Haley Stevens of Michigan each received $2.2 million in support from Bloomberg’s super PAC in 2018; in the past week, each has given him a glowing endorsement.

All told, Bloomberg spent $8.9 million supporting Rouda, Sherrill and Stevens — nearly a quarter of his total spending in the midterms.

Rouda, Sherrill and Stevens all denied that their endorsements were tied to Bloomberg’s political largesse. “Using today’s vernacular, there was no quid pro quo,” Rouda told McClatchy when pressed about the connection.

“Some of the candidates Mike has supported over the years have supported his presidential campaign, many have not,” said Stu Loeser, a longtime Bloomberg spokesperson. “But Mike is hardly alone in building relationships with candidates who later supported him ― other 2020 Democrats have gone out of their way to show that they were doing the same thing.”

The correlation highlights the power of Bloomberg’s extraordinary personal fortune to warp the Democratic presidential primary.

His estimated net worth is more than $50 billion, making him one of the richest people on the planet. Since entering the presidential race less than three months ago, Bloomberg has spent north of $300 million of his wealth playing catch-up to candidates who have been campaigning for a year or more. It’s working: Bloomberg has amassed more TV airtime, polling support and prominent endorsements than some candidates have accrued over more than a year of arduous campaigning. And he is polling high enough in some national polls to meet one of the qualifications for the Democratic debate stage.

A former Republican, Bloomberg has also secured roughly as many endorsements from party leaders as two of the current front-runners, former Mayor Pete Buttigieg and Sen. Bernie Sanders.

Many of those throwing Bloomberg their support are mayors whose cities have benefited from seven- and eight-figure donations from Bloomberg’s vast network of philanthropies. Others have personally attended an elite, Bloomberg-financed boot camp for mayors. Stevens cited her past work as a fellow with Bloomberg Philanthropies as one of the reasons for her endorsement.

The endorsements from Rouda, Sherrill and Stevens stand out because House Democrats are being unusually slow this cycle to make endorsements. More members of Congress had endorsed Hillary Clinton by this point in 2016 than have endorsed any of the candidates running in 2020 thus far. Of the 232 Democrats in the U.S. House, more than 100 remain undeclared. Nine are currently endorsing Bloomberg.

Rouda, Sherrill and Stevens received Bloomberg’s support in the form of TV ads bought by a super PAC, Independence USA PAC, which receives all of its money from Bloomberg and his gun control advocacy group.

Isabella Carapella/HuffPost Some 23% of Bloomberg's electoral spending in 2018 went to three House Democrats who are now endorsing him for president.

In the past, Bloomberg has used the PAC to support Republicans and Democrats. But in 2018, he spent $38.1 million supporting only Democratic candidates in 33 House and Senate races. Rouda, Sherrill and Stevens were the second-, sixth- and seventh-largest beneficiaries, respectively, and their races accounted for 23% of what the super PAC spent.

The spending against Rouda’s opponent accounted for an astonishing 12% of what all candidates, parties and interest groups spent on the race. Bloomberg’s spending pushed Rouda’s race into the 10 most expensive in the country that year.

Like Rouda, Sherrill and Stevens are moderate, suburban Democrats who peeled off traditionally Republican districts in the 2018 blue wave.

Sherrill, who supported Sen. Cory Booker until he dropped out of the presidential race, cited Bloomberg’s support for gun control and infrastructure projects in making her endorsement. A spokeswoman for Sherrill said the congresswoman and Bloomberg have met and had “productive” interactions but did not give specifics.

Stevens’ office said her two-year fellowship with the city of Louisville, Kentucky, which was sponsored by Bloomberg Philanthropies, figured into her endorsement.

“I have seen him build a strong team to tackle tough problems,” Stevens said in a statement, “and I think his unique combination of public and private sector leadership make him the best candidate to unite the country and defeat Donald Trump.”