Rep. Ciro Rodriguez (search) filed a much-anticipated lawsuit Wednesday challenging a Democratic primary recount that swung the results of the election in his opponent's favor.

Rodriguez led by 150 votes after last month's primary, but a recount requested by opponentHenry Cuellar (search) found 419 previously untallied ballots in the Cuellar strongholds of Webb and Zapata counties. Cuellar, a former Texas secretary of state, finished with a lead of more than 200 votes.

The lawsuit says there is no reasonable way to explain how so many new votes appeared. The suit asks the court to declare Rodriguez the winner or to order a new election in the district, which runs from the San Antonio area to the Mexican border.

"In some 30 years that I have been an administrator, supervisor or involved in elections, I have never seen this large a change in any county in any election," said Rodriguez lawyer Buck Wood.

The lawsuit did not make specific allegations of wrongdoing or name anyone in particular.

Cuellar said he was confident about his victory and that it was won fairly.

"The results of the recount are clear," he said. "I am confident that the court will acknowledge the voters' decision."

About a dozen Cuellar supporters waved signs outside the courthouse at passing cars. One sign said, "You lost: Get over it." Another had a picture of a crying baby inside a red circle, with a slash through the picture.

Wood, a veteran of legal battles over elections, said he expects a trial to get under way quickly and be wrapped up within a month.

The district's boundaries were substantially redrawn during last year's heated redistricting battle led by the Republican-led legislature.

Cuellar, a former ally of Rodriguez, had planned on running in a different district, but the redrawn map made that district more solidly Republican. So he decided to run in Rodriguez's redrawn district, which is overwhelmingly Democratic.