Photo: Kin Man Hui, Staff / San Antonio Express-News Photo: Kin Man Hui /San Antonio Express-News Photo: Tom Reel, Staff / San Antonio Express-News Photo: Courtesy Hispanic Chamber Of Commerce Photo: Courtesy Toyota Motor North America

WASHINGTON - U.S. Rep. Joaquin Castro has decided not to seek the Democratic nomination next year to challenge U.S. Sen. Ted Cruz, according to Democratic sources, clearing the way for a likely Senate contest next year between Cruz and U.S Rep. Beto O’Rourke of El Paso.

Castro, of San Antonio, is expected to announce soon that he will bypass the contest to focus on his work in the House, which includes a coveted seat on the House Intelligence Committee.

Castro campaign aides declined to confirm the decision.

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Castro declared last summer that he planned to weigh a campaign against Cruz and he has done so during a tumultuous period for national security. Castro also is a member of the Foreign Affairs Committee.

Castro, 42, is viewed as one Texas’s most popular and aggressive young Democrats, along with twin brother Julián, a former San Antonio mayor who returned home in January after 30 months heading the Department of Housing and Urban Development in the Obama administration.

A Texas Lyceum poll in early April showed Joaquin Castro with more support than Cruz, 35-31 percent, a lead just outside the survey's margin of error. The survey showed Cruz and O’Rourke running neck-and-neck.

The early poll also found that nearly one-third of Texas voters hadn't thought about the Senate race enough to have an opinion.

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Castro might have held an advantage over O’Rourke in a primary given his work to build the Texas Democratic Party, which hasn’t captured a statewide election since 1994.

But whoever won that contest likely would have emerged bruised and drained of a portion of the significant resources needed for the run at Cruz.

Castro’s decision also suggests an awareness of potential damage to his political future from losing to Cruz, who ran for the GOP presidential nomination last year and has cultivated a national following among ardent conservatives despite sitting in the Senate less than a full term.

blambrecht@express-news.net