California congressman announces presidential bid on 'The Late Show' with Stephen Colbert
Rep. Eric Swalwell (D-CA) on 'The Late Show' with Stephen Colbert (screengrab)

The list of Democrats who are running for president expanded again on Monday when a fourth-term congressman from California announced his campaign.

Rep. Eric Swalwell (D-CA) made the announced during taping of "The Late Show" with Stephen Colbert, which will air Monday evening.

"I've already done a lot, but I can do more," he said. "I'm ready to solve these problems, I'm running for president of the United States.