In a rare joint statement, two Democrats opposing each other in a House primary in Arizona came together Tuesday to blast a third Democrat for lobbying "Karl Rove-styled attacks" and demand that he end what they described as a pattern of underhanded campaigning.

The third Democrat shot back, dispatching top allies to accuse his opponents of using race to divide the party's voter base. 

State Sen. Kyrsten Sinema and state Senate Minority Leader David Schapira called on Andrei Cherny, a former Clinton aide, to "end his brand of sleazy campaigning and focus on the real issues."

"We are calling on Andrei Cherny to stop his Karl Rove-styled attacks and asking him to join us in running an issue-focused campaign for the Democratic nomination," Sinema and Schapira wrote Tuesday.

The rebuke followed a flare-up over campaign mailers Cherny sent during a 2002 race that offended fellow Democrats. After initially defending the mailers, Cherny apologized Monday for the flyers, which used a photograph of a tattooed African American with a gun to suggest that voters would be unsafe under Cherny's opponent.

But Sinema and Schapira said the underhanded tactics didn't stop with Cherny's 2002 campaign for California state Assembly. Rather, they said, Cherny's congressional campaign has been circulating false information to rightwing publications, mischaracterizing news articles and using guilt by association to lob unfair attacks at fellow Democrats.

Schapira told The Hill that Cherny's sleaziness in the campaign thus far had been unmatched.

"Mr. Cherny needs to understand that just saying something doesn’t make it true," said the two Democrats. "We agree that despite Mr. Cherny’s public comments to the contrary, he is the only Democrat in this race running a negative campaign."

Supporters for both Sinema and Schapira held a news conference Tuesday to call Cherny out for the offensive flyers. In response to the event, Cherny supporters turned the tables on his rivals, accusing Schapira and Sinema of divisive campaign tactics for suggesting that Cherny's flyers had been racist.

Phoenix City Councilman Michael Nowakowski (D), who endorsed Cherny last week, called the uproar over the flyers “the most disgusting kind of politics I’ve ever seen in the Democratic Party," while state Rep. Ruben Gallego, a Democrat whose advocacy on immigration reform has given him a national profile, announced he was endorsing Cherny — in part to rebut the attacks from Sinema and Schapira.

And Terry Goddard, the 2010 Democratic gubernatorial nominee and one of the state's most prominent Democrats, said Sinema and Schapira were smearing Cherny over views they know he doesn't hold. 

“I am disappointed that Kyrsten Sinema's and David Schapira's campaigns are making irresponsible attacks instead of dealing with the important issues facing our country,” Goddard said in a statement. “I considered them honorable, high quality Democratic candidates, so it grieves me to see them take this path."

Sinema and Schapira did not attend the news conference, where supporters insinuated that Cherny's mailers had been indicative of a racist attack. But both campaigns acknowledged that they had encouraged supporters who were interested to attend the event.

At issue are three direct-mail flyers Cherny's campaign sent out in 2002, when Cherny was 26 years old and running for state office in California. Two of the mailers were said to have mischaracterized his opponent's positions, while a third struck some as racially distasteful.

That mailer showed a red-tinged photo of his opponent, Lloyd Levine, next to a photo of a shirtless African-American man with tattoos pointing a gun at the camera and sneering.

"Gangs, graffiti, rapists and thugs. Our streets aren't safe with Lloyd Levine," said the mailer.

Major Democratic officials yanked their endorsements for Cherny while others backed his opponent. Antonio Villaraigosa, the former assembly speaker who now serves as mayor of Los Angeles, joined those criticizing Cherny, according to a report in the Los Angeles Daily News.

The Hill reported last week that Sinema had pointed to the mailers from 2002 and the reaction from Democrats as an example of what it deemed questionable campaign tactics by Cherny. Soon after, reports of the mailers spread in blogs and local Arizona media, prompting a response from on Monday from the Cherny campaign.

"It was one flier more than 10 years ago and not reflective of the work I've done over more than 15 years or the way I've waged this campaign," Cherny said. "Most of all, it has nothing to do with any of the issues facing the people of the 9th congressional district."

Cherny, Sinema and Schapira are squaring off in the Democratic primary for a competitive seat in central Arizona created after the 2010 U.S. Census showed rapid population growth in Arizona.

One of the Republicans vying for the seat, Vernon Parker, was endorsed Tuesday by former President George H.W. Bush. Parker worked in Bush's administration, as well as that of his son.

The Hill rates this race as a toss-up.

- This story was posted at 8:20 p.m. and has been updated.