President Obama launched a scathing attack on Rep. Darrell Issa (R-Calif.) at a fundraiser in San Diego on Sunday night, calling his recent move to portray himself as an administration ally “shameless” and “the definition of chutzpah.”

In the latest sign of how Democrats are hoping to expand the map in this fall’s congressional races, Obama devoted much of his remarks at the Democratic Congressional Campaign Committee fundraiser to blasting the longtime House Republican who has overseen multiple oversight investigations in recent years, including investigating Democratic presidential nominee Hillary Clinton.

Issa chaired the House Oversight and Government Reform Committee from January 2011 to January 2015 and is now in a close race against retired Marine Doug Applegate. Issa, who launched investigations of issues including the Internal Revenue Service’s treatment of conservative groups and the attack on a U.S. diplomatic post in Benghazi, Libya, recently sent a mailer with a photo of Obama signing legislation providing new federal legal protections to victims of sexual assault. The brochure says Issa was “pleased” the president signed the law, which he co-sponsored.

The president told more than 60 donors, who had paid at least $10,000 to attend, that “Issa’s primary contribution to the United States Congress has been to obstruct and to waste taxpayer dollars on trumped-up investigations that have led nowhere. And this is now a guy who, because poll numbers are bad, has sent out brochures with my picture on them touting his cooperation on issues with me.”

“Now, that is the definition of chutzpah,” he said as members of the crowd at supporter Christine Forester’s home laughed. “Here’s a guy who called my administration perhaps the most corrupt in history despite the fact that actually we have not had a major scandal in my administration, that when Trump was suggesting that I wasn’t even born here, said, well, I don’t know, was not sure. We can pull up the quotes.”

In case the group hadn’t gotten the message, Obama said of Issa’s recent campaign brochures, “Now, that is shameless.”

Issa issued a statement Monday saying he was “disappointed but not surprised that the president, in a political speech, continues to deny accountability for the serious scandals that happened under his watch where Americans died overseas and veterans have died here at home.”

“You’d be hard pressed to find anyone who thinks I’ve done too much to hold Washington accountable,” Issa said. “I’ve worked with the administration on good legislation where it was possible, called out wrongdoing wherever I saw it and will continue to do so.”

The president did offer Issa and some of his other GOP critics one modest compliment Sunday, saying they were always eager to pose with photos of him during holiday parties.

“To his credit, I will say that he has been very pleasant to me at our Christmas parties,” he said as the group laughed again. “No, he is. I’m serious. . . . This is true — a number of Republican caucus members, like Michele Bachmann, they’ll show up and there’s like good cheer and bipartisanship for one evening.”

After referring to the former Minnesota congresswoman and unsuccessful Republican presidential candidate, Obama added, “Some of them say, I’m praying for you. And I don’t question the sincerity that they are praying for me: ‘Please, change this man from the socialist Muslim that he is.’ ”