The matchup between California Democratic Reps. Howard Berman (right) and Brad Sherman is expected to be one of the most expensive House races ever and has divided the delegation, with 23 of the state's 32 other Democrats endorsing Berman and two backing Sherman.
Because of that, Mitchell said to expect a "mountain of spending in the primary," as neither wants to be the candidate who lost by 2,000 votes with $4 million in the bank. Berman has already sent out one mailer touting his own leadership.
Sherman has held more than 150 town hall meetings since coming to Congress, something his campaign believes will be the difference in the race.
"Both candidates will have plenty of money to communicate. This will not determine the winner," Sherman adviser Parke Skelton said. "The winner will be the Member who has done the best job of building a base in the San Fernando Valley. That will be Brad."
In an interview, Sherman said Berman's role in helping keep incumbents safe for the past 10 years led to the disparity in endorsements. He said his own record and promise of constituent outreach will make the difference with voters.
"They want someone they know they're going to see in 2013, 2014 and 2015," Sherman said. "I'm going to be at the concerts in Warner Center Park standing by my constituent service booth in 2028."
Skelton also downplayed the importance of Berman's overwhelming lead in Congressional endorsements. Far more important, he argued, is Sherman's support from local leaders, unions, Democratic activists and volunteers, and the Democratic Party of the San Fernando Valley.
But Berman and his allies say his overwhelming support from the delegation — from Rep. Mike Thompson's district near the Oregon border to Rep. Bob Filner on the border with Mexico — should be a sign to voters in the valley that Berman's colleagues believe he is the more effective Member of Congress.
"There is a larger story in the numbers, 23 to two," Berman said. "That's that the people that work with us every day on legislative issues and all kinds of things for California have decided they're willing to publicly associate with one of us — with me."
One of the few remaining neutral California Democrats is Rep. Janice Hahn, the newest Member of the delegation and one dealing with a Member-vs.-Member race of her own against fellow Democratic Rep. Laura Richardson in south Los Angeles. Hahn said she's been focusing on her own race so far but may eventually weigh in on the Sherman-Berman bout.
Los Angeles-based Democratic consultant Roy Behr doesn't see much of an effect from the endorsements on voting in a race between two longtime incumbents. It could make a difference with donors, he said, "but neither of these guys are short on money."
"Given the candidates' similarities in voting records, experience, appearance and even names, I think the race will be won by whichever one does a better job of emerging from the blur of similarity," Behr said.
Mitchell cautioned that Berman could be setting himself up for an attack line from Sherman by hyping his influence and insider status in Congress, especially if that's not the message voters are listening for this year.
Former Sen. Scott Brown, R-Mass., candidate for U.S. Senate in New Hampshire, holds his hand over his heart during the singing of the national anthem as he waits to take the stage for his town hall campaign rally with Sen. John McCain at the Pinkerton Academy in Derry, N.H., on Monday, Aug. 18, 2014.