"Where have you been, Loretta, for the past 14 years? Where is the leadership of your party and your president?" said Tran.
Representing the 47th Congressional District for 14 years, Sanchez is facing her most serious challenge yet. Tran, a Republican assemblyman for five years, criticized Sanchez's support of the federal stimulus package.
"Where are the jobs? Really, we're talking about the stimulus package in which this Democratic Congress has passed with President Obama's approval, $787 billion," said Tran.
"We didn't create this mess. But we'll take responsibility to fix it. For small businesses, we're putting in tax incentives to hire people and we've cut taxes on 95 percent of the people -- the middle class," said Sanchez.
The district covers Santa Ana, Garden Grove, part of Anaheim and Fullerton. Nearly half of voters are registered Democrats, and nearly half were born outside the U.S.
Sanchez is proud to be the daughter of immigrants. Tran fled Vietnam with his family before the fall of Saigon.
In a Spanish-language TV interview, she said "the Vietnamese and Republicans" are trying to unseat her. She was criticized for the comment. She later said it was misinterpreted.
"I'm still waiting for the congresswoman to apologize to her own constituents, because it was offensive," said Tran.
A third candidate, Cecilia Iglesias, was not invited to the debate. She could play a crucial role running as an independent. Her family came from El Salvador. Some believe Iglesias could split away votes from Sanchez in a district where more than 70 percent are Latino.