The Capitol’s dome is seen at dawn. (J. Scott Applewhite/AP)

Tickets worth $7,236 to the Santa Fe Opera for a Democratic senator from New Mexico and his supporters. Nearly $19,000 in tickets to the two-day horse race at the Breeders’ Cup for a Kentucky GOP congressman and his racetrack guests.

In both cases and many more like these, the money came from a loosely regulated pot of money that lawmakers use to advance their standing in Congress and support other members’ reelection campaigns.

A report released Thursday by two advocacy groups seeking greater regulation of campaign finance offers insight into the swanky world of fundraising for political action committees known as leadership PACs — at five-star resorts, high-dollar events and exclusive golf clubs.

Leadership PACs were established in 1978 by then-Rep. Henry A. Waxman (D-Calif.) to help like-minded Democratic lawmakers advance to higher-ranking positions in Congress. The idea was to let members raise money for their allies on the Hill through fundraising vehicles separate from their campaign committees. The money is often used for what’s called donor cultivation: feting wealthy supporters in the hopes that they will write big checks back to the leadership PAC and other committees.

Over the years, leadership PACs have become must-have accessories on Capitol Hill. Currently, 486 of 535 members of Congress have at least one leadership PAC, according to the Center for Responsive Politics.

Even in the era of big-money super PACs, which can raise and spend unlimited amounts of money per election cycle, leadership PACs remain essential on Capitol Hill. They are so ubiquitous that even first-time federal candidates establish their own during their campaigns — long before ballots are cast.

They help members signal to their colleagues and donors that they are ambitious and serious players, said Marian Currinder, a senior fellow with the free-market think tank R Street Institute’s Governance Project who has studied the growth of leadership PACs.

“It seems that the usefulness of them is more of an intra-institutional use, in that it’s still a way for members to demonstrate to party leadership and the steering committees and to their colleagues that they are team players,” Currinder said.

The report, by the Campaign Legal Center and Issue One, says that lawmakers routinely use leadership PAC money to support a “lavish” lifestyle of mingling with donors and supporters. Fundraisers held at exclusive golf clubs and beach and ski resorts were common expenditures, the report says.

Yet the amount each leadership PAC spends to support other campaigns and candidates varies widely, the report finds. For example, during the 2016 cycle, one leadership PAC spent just 3 percent helping candidates or political committees, while another spent 97 percent.

“It is one thing to contribute to a candidate in order to support their run for office; it is another to fund an officeholder’s trip to Vegas and their stay at the Venetian,” the report says.

Lawmakers and congressional campaign aides say the expenses are par for the course and that it takes money to raise money.

Campaign aides said that determining what constitutes a “lavish” lifestyle is subjective and that any thresholds that the advocacy groups are using are arbitrary standards to decide how much leadership PACs should be contributing to campaigns.

“You want to make it so that donors feel comfortable, feel welcome and have fun. That’s Fundraising 101,” said one GOP campaign aide familiar with leadership PAC fundraising who spoke on the condition of anonymity to talk frankly about strategy.

The groups analyzed Federal Election Commission data from January 2013 through March 2018 and complemented their research with data on leadership PAC spending by the nonpartisan Center for Responsive Politics.

The report highlights high-end expenses. Unlike with their campaign committees, lawmakers face virtually no limits on how to spend leadership PAC money.

In one case, a leadership PAC supporting Sen. Rand Paul (R-Ky.) spent nearly $30,000 on travel, lodging and other expenses related to a trip to Malta and Italy around August 2017, FEC records show.

According to a news release, Paul traveled to Malta around that time to meet with the country’s leaders in his official capacity. A representative for the leadership PAC did not respond to requests for comment.

The groups urged the FEC to impose limits on leadership PACs, particularly limiting expenses that could be considered “personal use.” This restriction currently applies to lawmakers’ candidate committee spending.

Without the restriction, there is room for abuse, the authors said.

“The assumption is that these are political committees established by current or aspiring members in leadership to support their colleagues,” Brendan Fischer, who directs the Campaign Legal Center’s federal regulatory work, said in an interview. “Over time, the use of leadership PACs expanded, and as leadership PACs expanded, leadership funds have increasingly been abused.”

Several leadership PAC aides said their expenses were spent directly for the purpose of fundraising and that the lawmakers did not personally benefit.

The Santa Fe Opera tickets were for the supporters of LOBO PAC, supporting Sen. Martin Heinrich (D-N.M.). The $7,236 mentioned in the report paid for almost 100 tickets, said the leadership PAC’s spokesman Steve Fitzer.

“Of the funds you have mentioned, about $350 was spent on tickets for the Senator personally and his wife so they could join their guests at the opera,” Fitzer said.

Meredith McGehee, executive director of Issue One, said that even if the leadership PACs are paying for fundraisers, they still allow lawmakers to live large.

“It doesn’t hide the fact that under the guise of a campaign event, you get to live a lifestyle that many Americans would love to have someone else pay for,” McGehee said. “The difference here is, you’re an officeholder. You’re a public servant.”

One expense included in the report was a $4,680 payment to Steelers Ticketing in January 2018 by the Keystone Fund, a leadership PAC tied to Rep. Mike Doyle (D-Pa.).

When asked about the expense, Doyle said it was a “one-time, one-day event” to raise money for the PAC.

“I rented the box and bought tickets, then sold the tickets to donors, who would then make a donation to the leadership PAC. Then the leadership PAC would get the profit, then pay candidates that I support,” Doyle said.

“That’s not very much of a lavish lifestyle expenditure. It was a couple hours, and the Steelers lost, which made the day not that enjoyable,” Doyle said. “We lost to the New England Patriots, which is a team I can’t stand.”