An ex-Senate aide defeated a former city councilwoman in a runoff election Tuesday as Houston-area Republicans chose a nominee for former House Majority Leader Tom DeLay's old congressional seat.

Pete Olson overpowered Shelley Sekula Gibbs with 68 percent of the vote to her 31 percent in unofficial, complete returns. The winner will face first-term Democratic Rep. Nick Lampson. Sekula Gibbs got the most votes in March in the 10-candidate Republican field.

Sekula Gibbs, a former Houston City Council member, temporarily held the office after DeLay resigned his congressional seat in 2006 following his indictment in a Texas campaign finance case. Olson is a former aide to U.S. Sens. Phil Gramm and John Cornyn.

In the race for district attorney of Harris County, which includes Houston, Pat Lykos, a former police officer and judge, defeated Kelly Siegler, a flamboyant prosecutor, with 53 percent of the vote to 47 percent to gain the Republican nomination.

Chuck Rosenthal resigned as district attorney amid a contempt of court charge and a scandal involving racist, pornographic and political e-mails found on his county computer. Some were sent by Siegler's husband, physician Sam Siegler. Kelly Siegler attempted to distance herself from the e-mails but took heat for her unorthodox, rule-bending courtroom style.

Lykos, who says the office needs a leader who's not connected to the scandals, will face Democrat C.O. Bradford, a former Houston police chief whom Rosenthal once charged with perjury. Bradford was accused of lying under oath about the chastising of a subordinate, but a judge summarily acquitted him after prosecutors laid out their case.

In Austin, two Democrats competed to become the successor to longtime Travis County District Attorney Ronnie Earle, whose office houses a public integrity unit that investigates alleged corruption in state government.

Candidate Rosemary Lehmberg defeated opponent Mindy Montford with 65 percent of the vote to 35 percent. Both are assistants to Earle. Earle's office brought the charges against DeLay, who maintains his innocence and claims the case against him is politically motivated.

"The people in Austin want their district attorney to have Austin values," Lehmberg said after her victory. She's expected to take office next year, becoming the first woman to hold the job, because there is no Republican running.

In a Democratic congressional runoff in Dallas, Eric Roberson defeated Steve Love in District 32 to become the nominee to run against incumbent Republican Rep. Pete Sessions.

In California, former legislator Jackie Speier avoided a runoff for a San Francisco Bay area congressional seat Tuesday, winning a special election to fill the vacancy created by the death earlier this year of fellow Democrat Tom Lantos.

Speier had nearly 78 percent of the vote with 71 percent of precincts reporting. She needed more than 50 percent to avoid a June 3 runoff election.

The victory will send Speier to Washington representing the same congressional seat once held by her boss, former Rep. Leo Ryan. Speier was an aide to Ryan and accompanied him on a fact-finding mission to Guyana in 1978 to investigate claims that cult leader Jim Jones was holding followers against their will. A shooting on an airport runway left Ryan and four others dead and Speier severely wounded.

Speier, a 57-year-old Democrat, has since represented much of the area within the 12th Congressional District as a San Mateo County supervisor, assemblywoman and state senator.