Colorado Democrats and their allies are demanding that U.S. Rep. Mike Coffman give back $20,000 in campaign contributions from former Rep. Aaron Schock’s political action committee following the Illinois Republican’s ignominious fall from office.

A Coffman spokesman said the Aurora Republican has already donated the Schock contributions to a veterans organization and dismissed the furor as left-wing hysteria.

Schock, a media darling and prodigious fundraiser who resigned his seat last month amid a cascade of revelations about his lavish spending of taxpayer dollars, has been supporting Coffman’s congressional runs through his PAC, known as the GOP Generation Y Fund, since Coffman first won the seat in 2008.

Donations from Schock’s PAC to Coffman’s campaign coffers included $5,000 in 2008, $5,000 in 2011, $5,000 in 2013 and $5,000 in 2014. (Schock’s PAC also made $5,000 donations in the last cycle to Colorado Republicans Doug Lamborn and Ken Buck.)

Schock resigned three weeks ago after news broke that he had billed taxpayers and his campaign for 170,000 miles traveled on his personal vehicle, although the car’s odometer displayed only 80,000 miles when he sold it. Schock had already been under scrutiny for redecorating his office in the posh style of the BBC show “Downton Abbey” and for treating staffers to a Katy Perry concert and other pricey events.

Republicans were swift to pounce on U.S. Sen. Michael Bennet after New Jersey Sen. Robert Menendez, whose PAC contributed to Bennet’s 2010 campaign, came under indictment on federal corruption charges last week. Bennet, who faces what could be one of the toughest reelection bids of any Senate Democrat next year, plans to donate the $10,000 received from the Menendez New Millennium PAC to charities that serve veterans in Colorado, campaign sources said.

In a statement issued on Wednesday, Colorado Democratic Party spokesman Andrew Zucker called it “hardly a surprise” that Coffman has accepted $20,000 in “shady campaign cash” from Schock. Zucker noted that Coffman and Schock served together on the House Small Business Committee and have co-sponsored legislation.

Liberal attack group ProgressNow Colorado also issued a call on Wednesday for Coffman to give up Schock’s “dirty money,” pointing to a story on the Colorado Independent website that said Coffman’s office hadn’t responded to inquiries about the contributions.

“We donated the money after Aaron Schock resigned and donated it to a veterans organization,” Coffman spokesman Tyler Sandberg said. “As a matter of principle we don’t respond to fake news websites, nor did we feel a need to trumpet the donation. Sorry to upset the left-wing attack machine so desperate to find a flaw with Mike Coffman.”

Pointing to an October 2014 Politico story about jockeying for leadership of the National Republican Congressional Committee, Sandberg scoffed further at attempts to link Coffman and Schock as best buddies.

“The ridiculous thing about this attack is, anyone with access to Google knows that Mike Coffman and Aaron Schock didn’t get along,” he said. “Long before his deco-art scandals, Team Coffman smacked down Schock’s leadership bid.”

Democrats are pouring the heat on Coffman lately as reports surface that the Aurora Republican is considering challenging Bennet next year. Coffman, who hasn’t lost an election since winning a seat in the state House in the late 1980s, surprised even his most enthusiastic backers when he trounced former House Speaker Andrew Romanoff by a 9-point margin in the suburban 6th Congressional District race last year. By most accounts, it was supposed to be among the nation’s closest congressional contests, in part because the district is nearly evenly divided.

Coffman has been raising money for another run in the 6th CD, although he told a Washington newspaper recently that he’s undecided about a bid for the Senate seat.

“I haven’t decided. A lot of people want me to run but I haven’t made the decision,” Coffman said in a March 18 Washington Examiner story. “I’m focused on running for the House right now.”

Democrats are still searching for a candidate to run for Coffman’s congressional seat, though party insiders say Centennial City Councilwoman Rebecca McClellan has been testing the waters.

Bennet raises $2 million

U.S. Sen. Michael Bennet raised more than $2 million in the first quarter, his campaign announced this week, and has some $2.9 million cash on hand.

Bennet tops some rankings as the most vulnerable Democratic senator up for election next year following the announcement by Senate Minority Leader Harry Reid of Nevada that he won’t seek another term.

More than 80 percent of the donations were $100 or less, the Bennet campaign said. In total, the campaign counts nearly 30,000 contributions this cycle.

Campaign insiders pointed out that Bennet’s first-quarter total outpaces anything reported by senators facing competitive races at the same point in the last election cycle. Still, Ohio Sen. Rob Portman, a Republican facing what looks to be a close race against former Ohio Gov. Ted Strickland, announced last week that he raised $2.75 million this quarter.

“Michael’s proud of the support he’s received from grassroots donors across Colorado, and that’s reflected by our fundraising this quarter,” said Bennet campaign manager Dan McNally in a statement.

Candidates must file reports with the FEC by April 15, though some are announcing their numbers early.

The only Republican challenger who is actively campaigning against Bennet is El Paso County Commissioner Darryl Glenn.