Sherman is running for re-election, and his main competitor, fellow Democrat and incumbent Rep. Howard Berman, spent the day campaigning in Granada Hills.
The candidates had represented two different congressional districts, but with the lines redrawn, they're vying for one seat in District 30.
"I think the difference is effectiveness," Berman said. "Who can get more done for the San Fernando Valley back in Washington?" Berman said.
Both candidates say they have the proven track record. Sherman says where they stood on the original bail out of Wall Street is what sets them apart.
"My efforts to block the original TARP bill that resulted in a savings to this county of well over $400 billion dwarfs anything that my opponent claims to have done," Sherman said.
According to a recent online poll by the University of Southern California, nearly 32 percent of Valley voters support Sherman, 24 percent support Berman and 23 percent are undecided.
As the primary draws near, the candidates accuse the other of running a negative campaign. Sherman points to his competitor's trips as chairman of the Foreign Affairs Committee.
"He has gone on 163 free trips, most of them have been paid by private interests," Sherman said.
Berman said his trips have served the public interests.
The top two vote-getters Tuesday will face each other in November, so the runoff could include Berman and Sherman.