David M. Rubenstein, who last year announced a gift of $18.5 million to help renovate the Lincoln Memorial, will be presented with a key to the city on Jan. 12 by D.C. Mayor Muriel E. Bowser. (Bonnie Jo Mount/Washington Post)

D.C. Mayor Muriel E. Bowser has invited all 535 members of Congress to a cocktail reception Thursday night on Capitol Hill, embarking on a charm offensive in hopes that she can make inroads for the city with a new Republican-led Congress.

And Bowser, a Democrat, is beginning the campaign with a toast to one of the few D.C.-area residents who can draw a crowd from both sides of the political aisle: billionaire financier and well-known Washington philanthropist David M. Rubenstein.

Bowser plans to present Rubenstein with the highest honor she can bestow — a key to the city — in recognition of the millions he has given to restore such treasures as the Washington Monument and the National Archives while also bankrolling annual scholarships for a student from every D.C. public high school.

“When I consider a key to the city, I spend a lot of time thinking about it, making sure the recipient is someone who has made significant contributions to Washington,” said Bowser, who is hosting the party at the Cannon House Office Building. “David is a true patriotic Washingtonian, just the kind of person fitting of that honor.”

Bowser has presented two keys to the city, including one last spring to Nationals slugger Bryce Harper. The star outfielder prominently wore a “51st” state T-shirt during interviews last year as Bowser pushed for statehood for the nation’s capital.

President-elect Donald Trump watches as Caryle Group co-founder David Rubenstein departs after their meeting Dec. 28 at Trump’s Mar-a-Lago Club in Palm Beach, Fla. (Jonathan Ernst/Reuters)

Reached by phone on Wednesday as he was returning from Europe, Rubenstein said he was surprised and honored to receive the key and quipped that unlike the last honoree, it was not for his home-run record.

“I know I’m not getting this for my athletic skills, but I am honored,” Rubenstein said. “I hope it is seen as a symbol that business people have a fair bit to contribute to the city, and hopefully we can encourage other business people to pitch in and do some things to help the city in areas of their interests.”

The co-founder of the Carlyle Group, one of the country’s largest private-equity firms, agreed last month to fund an overhaul of the Washington Monument’s faulty elevator, a job that could cost $2 million to $3 million.

It was the second time Rubenstein stepped in to help keep the city’s iconic obelisk open to the public. Following an earthquake that damaged the monument in 2011, he donated half of the $15 million cost to repair cracks in the tower’s marble and granite.

Other gifts announced by Rubenstein in recent years include: $18.5 million to help renovate the Lincoln Memorial; $5.37 million to refurbish the U.S. Marine Corps War Memorial near Arlington National Cemetery; $10 million to Montpelier, the historic Orange, Va., home of James Madison; $5 million to the White House Visitor Center; $12.3 million to Arlington House, the home of Robert E. Lee; $4.5 million to the National Zoo’s giant panda program; and $13.5 million to the National Archives.

Rubenstein, a Baltimore native who lives in Bethesda, Md., has also served as chairman of the Kennedy Center and the National Book Festival, and he was recently elected chairman of the governing board of the Smithsonian Institution.

Beverly Perry, senior adviser to Bowser and a former top executive at Pepco Holdings, said the response to Thursday’s reception has been positive, with “hundreds” across the political spectrum on the Hill indicating they will attend.

President Obama and first lady Michelle Obama are joined by philanthropist David Rubenstein at the Kennedy Center Honors gala on Dec. 4. (Manuel Balce Ceneta/AP)

Perry was well known during her years as a federal lobbyist for hosting large parties. She began circulating invitations to members of Congress late last week, and said she hopes the event could begin to build relationships, especially between newer members of Congress and the city.

The invitations say the event is to honor both Rubenstein and to welcome the 60 new members. The announcement also lists almost every major business group in the city as a sponsor: Destination DC, the Economic Club of Washington, D.C., EventsDC, Federal City Council and the Greater Washington Board of Trade.

The gathering comes as some Democratic leaders in the city have expressed fear that conservative federal lawmakers, unchecked by a Democratic- ­controlled White House, could easily undermine D.C. laws on gun control, marijuana legalization and other social policies.

Rep. Jason Chaffetz, chairman of the House Oversight Committee, said last week that he would block a new law passed by city lawmakers legalizing assisted suicide. Chaffetz (R-Utah) has also said he will push to relocate federal agencies away from the District. And he was openly hostile last year to the idea of the District becoming a state, saying it would not happen as long as he controls the committee over District affairs.

Rubenstein said he thought the event Thursday could help build bridges, but he didn’t expect it to do much for Bowser’s quest for statehood for the District.

“When you reach my age,” said Rubenstein, 67, “I try to focus on things that can get done in my lifetime.”