LOS ANGELES

In an election that highlighted America's fluid racial landscape, an Asian American candidate emerged as the leading contender to fill a U.S. House seat in an overwhelmingly Hispanic district.

Democrat Judy Chu topped a field of 12 candidates Tuesday, making her the favorite to claim the seat in a July runoff. Democrats hold a more than 2-1 registration edge in the district.

If elected, she would be Southern California's only Asian American in Congress.

Voters looked beyond racial and ethnic identity and ``made their decisions based on who was best qualified and who had the deepest roots in the district,'' Chu said. ``I just think people heard my message about being a coalition builder.''

With all percent of precincts reporting, Chu had 31.9 percent, followed by fellow Democrat Gil Cedillo, a Hispanic state senator, with 23.4 percent.

Because no candidate cleared a majority, the top finishers in each party advance to a July 14 runoff.

The 32nd Congressional District seat had been in Hispanic hands since the 1980s. It was held by Rep. Hilda Solis until she resigned to become President Barack Obama's labor secretary.

But Chu's track record in the district -- she was mayor of Monterey Park and represented the area in the state Assembly -- helped her draw votes from across the racial spectrum.

The Republican winner, Betty Chu, shares Chu's surname, setting up the possibility of a runoff that could be confusing for voters.

Betty Chu had 10.4 percent of the vote and might have benefited from the visibility and campaign advertising of her better-known rival. The Republican Party's endorsed candidate, Teresa Hernandez, had 8.7 percent.

The only Libertarian candidate on the ballot, Christopher Agrella, also advanced to the runoff.

Two of three people in the district that runs from eastern Los Angeles into its suburbs are Hispanic, as are about half the voters. The district's population is about 20 percent Asian, 12 percent White and 2 percent Black.