With less than a week to go until Republicans choose a nominee in Texas’ 22nd district, former Senate aide Pete Olson has emerged with some key structural and political advantages in his runoff battle with ex-Rep. Shelley Sekula Gibbs.

But Sekula Gibbs remains a strong contender with formidable strengths — and with the unpredictable nature of voter turnout in Texas runoff contests, the race appears to be a virtual tie.

Both campaigns are claiming momentum heading into April 8, with voters in Fort Bend County, the home base of former Majority Leader and 22nd district Rep. Tom DeLay (R), likely to cast the deciding votes.

“I would say it’s still a tossup, leaning in Olson’s direction, and it’s going to come down to how well Pete does in Sugar Land to put him over the top,” said one Texas Republican insider, referring to Fort Bend County’s largest city. “Polling still has it neck and neck.”

Olson, with the backing of virtually the entire Texas House GOP delegation, not to mention House Minority Leader John Boehner (Ohio) and the House Conservatives Fund political action committee, has significantly outraised and outspent Sekula Gibbs in the runoff.

The pre-primary fundraising reports, filed March 19 with the Federal Election Commission, showed Olson with a $20,000 cash lead over Sekula Gibbs, while she was carrying $320,000 more in campaign debt than he was. The last pre-primary 48-hour contribution report filed by each candidate showed Olson in receipt of $10,500 and Sekula Gibbs in receipt of $1,000. Olson filed his last such report on Saturday; Sekula Gibbs filed hers on Monday.

Each camp is relying primarily on direct mail and radio ads to sway voters. But Olson had dropped approximately four mail pieces by the time Sekula Gibbs’ first piece hit mailboxes last month. Additionally, Olson was endorsed by Fort Bend County Judge Robert Hebert.

In Texas, county judges are important figures, and their endorsements can carry tremendous weight. The position is similar to that of county mayor as opposed to a trial court judge. Olson was also endorsed by former Sugar Land Mayor David Wallace and has the support of at least one popular conservative Houston talk-radio host, Edd Hendee.

But Sekula Gibbs has received the backing of 40 voting precinct chairmen, and that of another ex-Sugar Land mayor, Dean Hrbacek, who was a candidate in the March 4 Texas 22nd district GOP primary but failed to advance to the runoff. Sekula Gibbs entered the primary campaign with nearly 100 percent name identification and won last month’s primary with 30 percent of the vote, finishing first in a field of 10.

She earned a wealth of support running as a write-in against Rep. Nick Lampson (D) in 2006, when Republicans were prohibited from replacing DeLay on the ballot after he withdrew his name and resigned from Congress in June of that year following a victory in the March GOP primary. Sekula Gibbs is a former Houston city councilwoman, with her base in Harris County, second in importance in the 22nd district after Fort Bend County.

The Sekula Gibbs campaign believes it has strong support among the grass-roots GOP voters who tend to vote in runoff elections, and it is cautiously optimistic about Tuesday’s contest. Early voting began on Monday.

“We have volunteers all over the place,” Sekula Gibbs campaign spokesman C.B. Currier said. “Our grass roots are rocking and rolling. We feel real strong.”

As it did even before the March 4 primary, when it became clear that Olson and Sekula Gibbs were likely to advance to the April 8 runoff, the battle between the two has centered Olson’s status as a longtime Capitol Hill aide and Sekula Gibbs’ record as a councilwoman.

Sekula Gibbs has charged Olson with being a carpetbagger, on the grounds that he only moved back into the district to run for Congress. Olson notes that he was raised in the district and only left to attend the Naval Academy and later serve on the staffs of former Sen. Phil Gramm (R) and Sen. John Cornyn (R).

In recent days, Sekula Gibbs has also criticized Olson for helping Gramm secure funding for Interstate 69, a freeway in Texas that some conservatives believe will serve as the foundation for a Mexico to Canada transcontinental highway dubbed derisively as the “NAFTA Superhighway.”

But Olson has found plenty to chew on in Sekula Gibbs’ record, highlighting the spending spree she went on during her three weeks as a Congresswoman. Sekula Gibbs won a special election in November 2006 to fill out the remainder of DeLay’s last term, and Olson charges that Sekula Gibbs spent more on franking mail during her three weeks in office than most Members spend in a year.

Olson has also made sure her religious conservative supporters are aware that she previously supported taxpayer funding for abortions — Sekula Gibbs is now adamantly anti- abortion-rights — and that conservative Republicans generally are aware that as a Houston city councilwoman she supported spending city funds on day-laborer sites where illegal immigrants often wait to find work.

“I think Pete has firmly established himself on national security, illegal immigration and fiscal discipline. We are winning those voters that care about those issues,” said Chris Homan, Olson’s chief campaign strategist. “A lot of [those voters] happen to be high propensity Republican voters and older voters, two key elements you want to have going into a runoff.”