As Sen. Marco Rubio emerges as a strong contender for the presidential nomination, the ghosts that have haunted his past are threatening to come back around for another pass.

It’s the scandal-ridden gang that won’t leave him alone: Former Rep. David Rivera and former state Rep. Ralph Arza, who have been allies with Rubio since their political infancies, are both individuals with controversial pasts. Rivera has been under investigation as the alleged mastermind of a campaign finance scheme, and Arza was forced to resign from the Florida legislature in 2006 following two felony charges related to leaving a racial slur on a fellow representative’s voice mail.

The cloud of impropriety that hangs around Rivera and Arza should be noxious to a rising campaign with its eye on the White House. But both Arza and Rivera were spotted among other Rubio supporters as recently as the Republican presidential debates in Cleveland in August, three Republican sources tell The Daily Beast.

Opponents of the Florida senator’s campaign have seized on Rubio’s friendship with Rivera. During a presentation to donors last week in Houston, Jeb Bush’s campaign cited Rubio’s relationship with “scandal-tarred” Rivera as a reason why the senator is a “risky bet,” according to U.S. News & World Report.

The two may not realize that they are a liability for the Rubio campaign—or they may simply not care. There are certainly figures within the Rubio orbit who think the two are a distraction, and were irritated by their presence in Cleveland, but feel there is little they can do to prevent these former lawmakers from supporting him.

“Both Arza and Rivera would create political perception problems for Rubio,” wrote Manuel Roig-Franzia in the 2012 biography, The Rise of Marco Rubio. “But he had a tendency to stand by them, sometimes to his own detriment.”

It remains an open question precisely how close Rubio and Rivera still are. “Marco has addressed his relationship with David in the past, and I don’t have anything to add to those comments,” Rubio spokesman Alex Conant said in an email to The Daily Beast.

In a Washington Post profile of the Rivera-Rubio relationship in May, Rivera said that the two remained in touch. And in March, Rivera told Politico that the two had spoken “recently” by phone.

Rivera had been instrumental in launching and advancing Rubio’s political career, and for years the two were the closest of friends. When Rubio was formally voted in as speaker of the Florida House, for example, it was Rivera who nominated him.

In 2005 they purchased a home together in Tallahassee, which ultimately faced foreclosure at an inopportune time: just as Rubio was running for U.S. Senate. The house, which Politico called a “house of horrors” for Rubio’s political ambitions, was ultimately sold this year. (“I was discussing whether they needed a cleansing ritual with dead chickens, myself,” a family member of the couple who ultimately purchased the home told the Beast).

While Rubio publicly cut ties with Rivera, his former bestie has continued to get into trouble.

Rivera was hit with a $58,000 fine this year in connection with the improper billing of the state while a Florida House member. An ethics commission found that he expensed thousands in travel and other costs to the state while simultaneously reimbursing himself from campaign accounts.

But this is hardly the only ethics cloud hanging over Rivera. One alleged scheme, reported by the Miami Herald, detailed how Rivera helped run a shadow campaign in the Democratic primary, boosting prior unknown Justin Lamar Sternad to weaken a political opponent.

Rivera has been identified as a co-conspirator in the scheme, but he has not been charged and has maintained his innocence. Sternad saw prison time for his role in the case, as did Rivera’s former girlfriend, Ana Alliegro, who reportedly expressed consternation about why Rivera had not been charged in connection with the case.

Arza, who was alongside Rivera at the Cleveland debate and is another longtime friend of Rubio’s, has also seen his share of controversy. The former Florida lawmaker resigned in 2006 after being charged with two felonies, one for retaliating against and tampering with a witness. He ultimately pleaded guilty to two misdemeanor counts of tampering with a witness and was sentenced to probation, community service, an anger management program, and alcohol abuse counseling.

Neither Arza nor Rivera responded to The Daily Beast’s inquiries.