The Campaign for Primary Accountability, an anti-incumbent super-PAC, is likely to target longtime Rep. Pete Stark (D-Calif.) and could also target Rep. Joe Baca (D-Calif.) with big-spending campaigns this fall, according to a spokesman.

"I'm sitting in a meeting talking about him," group spokesman Curtis Ellis said when The Hill called to ask about Stark, who narrowly led his Democratic challenger in the first round of voting earlier this week. "Now that we've come through the first round of voting we're examining California, crunching the numbers, and certainly Pete Stark, like cream or something else, has risen to the top of our list."

California recently debuted an unusual primary system in which the top two vote-getters in the primary advance to the general election. Both Stark and Baca showed some vulnerability in the primary, and will face Democrats in the fall. Stark led his opponent by just six percentage points in the first round of voting, while Baca led his by nine points. Both are running in radically redrawn districts that include only parts of their old territory.

"Baca has been on our watch list and he's another long-term incumbent who faces a strong challenger from within his own party," Ellis said.

The group decided to stay out of the first round of voting in California because their goal is to target entrenched incumbents in safe seats rather than swing the seats to one party or another, and they had concerns that if they targeted incumbents in the first round the results would be uncertain.

Ellis said that the group has yet to look at whether it'll target Rep. Gary Miller (R-Calif.). In a surprise, Miller and California state Sen. Bob Dutton (R) both made the runoff, ruining Democrats' chances of winning a seat that gave President Obama 58 percent of its vote in 2008.

The super-PAC has spent hundreds of thousands of dollars in a number of primaries against longterm incumbents in safe seats, and played a big part in the defeats of Reps. Silvestre Reyes (D-Texas) and Jean Schmidt (R-Ohio).