Nestande was once chief of staff for former Rep. Mary Bono Mack (R-Calif.), and he said he started considering a run for Congress in the district after Ruiz defeated Bono Mack last election.

"Given the fact that Mary (Bono Mack) lost, and now we have a personality that is not my political ally here in office, that made me think about the process after the November election," he told the Palm Beach Desert Sun. "So I've redirected my thoughts and efforts into looking at the congressional seat."

Nestande has already brought on Bono Mack's old district director as a campaign spokesman.

Ruiz could be in for a fight: The district gave President Obama 51 percent of the vote, and its large Hispanic population means it may be harder to get the Democratic base out in a midterm election.