When Rep. Brad Sherman’s (D-Calif.) grabbed his opponent Rep. Howard Berman (D-Calif) at a debate on Thursday, he escalated the asperity in a campaign already marked by its nastiness.

The Berman camp was quick to seize on the incident, asking in one press release if Sherman had “lost his mind.” Though Sherman said he regretted his action the following day, Berman’s camp signaled the negativity was far from over.

Brandon Hall, Berman’s campaign manager, said all voters should be made aware of the incident and said he wouldn’t rule out running ads about it.

“We believe voters should be aware of (the incident),” he said in an interview with The Hill. “All options are on the table.”

Hall said the campaign is starting to bump up its paid communication and had already planned to start drawing a sharp contrast with Sherman’s negatives. He called it a common tactic. And Sherman’s act Thursday night simply provided “just another proof point” to hit.

The 30th congressional district is one of the few that pits senior Democrats against each other and one of the most expensive. Due to California’s new election format, the two candidates with the most votes in the primary advance to the general election, regardless of party.

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And the lack of discernible differences on policy areas has prompted both candidates to get personal, according to some who have followed the race.

Thursday night’s debate ruckus was a perfect example, said Jack Pitney, Claremont McKenna College professor. Rather than debating the merits of the DREAM Act, the two bickered about who cosponsored it.

The argument broke out surrounding whether Berman was the original sponsor of the bill that would grant citizenship to children brought to the country illegally if they enrolled in college or joined the military.

“The personality clash is so great because the issue difference is so small,” Pitney said.

Berman sponsored the current version of the DREAM Act and the one that passed the House in 2010. But Rep. Luis GutierrezLuis Vicente GutierrezBiden's inauguration marked by conflict of hope and fear The Hill's Campaign Report: Democratic primary fight shifts to South Carolina, Nevada Democrats rally behind incumbents as Lipinski takes liberal fire MORE (D-Ill.) introduced the first version of the bill in 2001. After the squabble at the debate, Gutierrez credited Berman for the current form of the legislation.

“Luis Gutierrez introduced the bill. You didn’t. And the official records of Congress will prove you wrong, “ Sherman shouted at one point during the debate.

Berman can be heard saying, “Wrong. Wrong.”

Standing opposite one another, Berman walked towards Sherman.

“Don’t you dare stand up here...[in the]…San Fernando Valley and get in my face,” Sherman shouted.

That is when Sherman grabbed Berman around the shoulder and said, “Do you want to get into this?”

Berman has served in Congress for 30 years and has the backing of key political figures. Sherman, on the other hand, says he cares more deeply about the newly drawn district, much of which is made up of Sherman’s former constituency.

The latest poll released late last month showed Sherman leading 45 percent to 32 percent for Berman, with 23 percent of voters still undecided.

Pitney said the dust up may give Berman a slight boost in the polls and fundraising, but it is unlikely to have a lasting effect or be the “proverbial game changer.”

He said TV advertising in California is extremely ineffective and expensive. And the message will likely not reach a large amount of voters.

The negativity has been bubbling up throughout the contest, and mudslinging from both campaigns began before the run-in at the debate.

Sherman has alleged that Berman paid his brother three quarters of a million dollars for managing non-existent campaigns.

Berman accused Sherman of exploiting campaign finance loopholes to take home nearly $500,000 in campaign loan interest.

Each has attacked the other for using a taxpayer-funded car for personal reasons.

Taylor Dark, a professor at Califronia State University, L.A., said the new California voting system is to blame and the personal nastiness will continue in the absence of clear policy differences.

“The episode mainly dramatizes the intense and highly personal nature of this kind of intra-party contest, which is itself a result of California's new redistricting system,” he said. “As always, primary contests easily become quite bitter and negative, especially in the absence of any clear difference between the candidates on the key issues.”