It’s a pure tossup.

That’s how Republican strategists view the race for the Republican nomination in Texas’ 23rd district, featuring wealthy attorney Quico Canseco and Bexar County Commissioner Lyle Larson.

Typical of primaries, the battle for the right to challenge Rep. Ciro Rodriguez (D) in November is likely to hinge on where voters turn out.

That could give Larson the edge, as he has represented a significant portion of 23rd district GOP primary voters at the local level for 16 years. But Larson entered the March 4 contest just this month, and for about a year Canseco has had the field to himself, and has campaigned hard throughout the sprawling southwest Texas district while introducing himself to voters via the radio and television airwaves and through their mailboxes.

“It’s very competitive,” a Republican insider based in the district said Tuesday. “I think they’re both on equal footing on the playing field.”

Former Rep. Henry Bonilla (R), who was ousted by Rodriguez in a December 2006 special election runoff, told Roll Call Tuesday that he is backing Larson.

In fact, a vast majority of the local GOP establishment is expected to support Larson, although Canseco has managed to secure the endorsement of some key Republican players in the district, which stretches from the western outskirts of San Antonio to the eastern edge of El Paso, and is banked to the south by the Mexican border.

“Lyle has a long history with the Republican Party, and as county commissioner was always very active in local politics,” said Bonilla, who is now a lobbyist with The Normandy Group in Washington, D.C. “He has an incredibly strong reputation.”

The Canseco campaign dismissed suggestions that Larson would win the GOP primary on the strength of greater grass-roots support, noting that it has spent more than $750,000 to date on its effort and plans on eclipsing the $1 million mark by the time the primary is over. Larson said he has raised $100,000 to date, adding that he expects to bring in around $400,000 by early March.

Canseco campaign spokesman Todd Smith said the money his candidate has spent has gone to building grass-roots support districtwide, including knocking on more than 10,000 doors in San Antonio and Bexar County — Larson’s stronghold — and funding several ongoing radio, television and direct-mail ad campaigns. Through Sept. 30, the candidate had loaned his campaign about $710,000, triggering the “Millionaires’ Amendment” of federal campaign finance law and enabling Larson to exceed normal campaign contribution limits.

Smith acknowledged that Larson’s name identification is high but contended that voters don’t know much about him. He said northwest Bexar County, which could determine who wins the primary, is chock-full of new voters who are less familiar with Larson and is an area that Canseco has been mining since he entered the race.

Canseco continues to knock on about 2,500 doors per week, Smith said.

“Lyle Larson got into the race late. Quico has been working very aggressively at the grass-roots level,” Smith said. “Lyle Larson doesn’t seem to be aggressive. I hope he continues to do exactly what he’s doing for the rest of the campaign.”

Not all Republicans familiar with the district are convinced that Larson’s financial disadvantage will translate into an electoral deficit on March 4.

According to one Texas-based Republican strategist, the outcome will revolve around who has the best voter-turnout operation. Because Larson is seen as the candidate with the most institutional GOP support, he could have the edge.

“It’s not just money, but boots on the ground. In that regard, one could argue that Lyle” is positioned to win, the GOP strategist said.

Larson agrees, although he contends that the $400,000 he expects to raise before the primary is enough to get his message out and dispatch Canseco. He argued in a telephone interview that his four years as a San Antonio councilmember and nearly 12 years as a Bexar County commissioner have put him in a better position to win the primary.

It is unclear at this point whether Canseco stands to benefit from the district’s large Hispanic population.

According to Larson, about 60 percent of the GOP primary vote will come from northwest Bexar County, which he has represented as a county commissioner since being elected in 1996. Larson chose not to enter the primary contest until January because jumping in sooner would have forced him to resign his position courtesy of Texas’ resign-to-run law.

Larson said he owed it to the voters who elected him to the county commission to retain his seat for as long as possible.

“We’ve exceeded our expectations,” Larson said of his Congressional campaign. “My opponent moved here earlier this year and is spending a lot of money. I don’t see him getting any traction.”

As it currently is drawn, the 23rd district is one of the largest in the nation. It is described as politically competitive but some statistics suggest it leans Republican.

Had the district existed in its present form in 2000, it would have delivered 53.6 percent of its presidential vote to then-Texas Gov. and now-President Bush. In 1998, it would have delivered 49 percent of its vote to then-state Attorney General and now-Sen. John Cornyn (R).

But the district is now held by Rodriguez, a Democrat. He beat Bonilla in a December 2006 special election runoff after a U.S. District Court redrew the 23rd district in the summer of 2006 to bring it into greater compliance with the Voting Rights Act.

Bonilla actually finished first in the special general election in the new district — which was held on the same day as the 2006 midterm elections. But in finishing with more than 48 percent, he still fell short of the 50 percent threshold he needed to avoid a runoff.

The 23rd district had been adjusted during the 2003 redistricting of Texas U.S. House seats engineered by then-Majority Leader Tom DeLay (R-Texas) in order to make it more politically safe for Bonilla, who over the years had been losing support among Hispanic voters. In a legal challenge to the 2003 redrawing, the Supreme Court ruled that Hispanics — who tend to vote Democratic — had to be added back to the 23rd district.

Republicans in Texas say defeating Rodriguez this November will be difficult, but legitimately possible.

Rodriguez, who previously served four terms representing the nearby 28th district before being ousted in a testy 2004 Democratic primary, was never an aggressive fundraiser during his first stint in Congress. But after losing his seat and one comeback attempt, he appears to be raising money more steadily and had $661,000 in the bank at the end of the year.

The 23rd district has yet to earn a spot as a top priority on GOP target lists circulating in Washington, D.C. The National Republican Congressional Committee rarely mentions the 23rd district when discussing its 2008 pickup opportunities, and Texas Republicans serving in the House know little about either Canseco or Larson, according to a Republican familiar with the delegation.

“This is definitely not in the top ten,” the Republican said. “It’s a hard district.”