WASHINGTON — U.S. Rep. Joaquin Castro said Monday that he won’t seek the Democratic nomination next year to challenge U.S. Sen. Ted Cruz, clearing the way for a likely Senate contest between Cruz and U.S Rep. Beto O’Rourke of El Paso.

Castro, of San Antonio, said in a statement that he intends to remain focused on his work in the House, where his committee assignments include a coveted seat on the Permanent Select Committee on Intelligence.

“With the threats posed by Russia and North Korea, coupled with the reckless behavior of this administration and their failure to invest in economic opportunity for the American people, at this time I believe I can best continue that work by focusing on my duties in the House Foreign Affairs and Intelligence committees,” his statement read.

Castro thanked those who had encouraged him to run and said he would be traveling in Texas for Democratic candidates. He made no mention of O’Rourke in his statement, but an aide said it was likely that Castro would be working on O’Rourke’s behalf.

“This is just the beginning, so keep it up. Our work is just getting started,” Castro said to those who offered him encouragement at rallies.

Castro, 42, is viewed as one of Texas’ 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 Housing and Urban Development Department in the Obama administration.

A recent poll showed Joaquin Castro slightly leading Cruz among registered Texas voters in a hypothetical matchup.

But Castro’s decision suggests an awareness of potential damage to his career 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 for less than a full term.

Castro, first elected to the House in 2012, declared last summer that he intended to weigh a campaign against Cruz, and he has done so during a tumultuous period for politics and national security.

President Donald Trump’s negative ratings early in his presidency and the failure by Congress with key initiatives thus far suggest potential midterm election peril for GOP candidates.

Meanwhile, a Texas Lyceum poll conducted early last month showed Castro with more support than Cruz, 35 percent to 31 percent, just outside the poll’s margin of error. The poll showed Cruz and O’Rourke running neck and neck.

But the early survey also found that nearly one-third of voters hadn’t thought enough about the Senate race to have an opinion.

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

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

Texas Democratic strategist Matt Angle observed that unseating Cruz likely will be a stiff challenge.

“By everybody’s measure, it’s an uphill slog,” said Angle, executive director of the Lone Star Project, an organization that promotes Democrats in Texas.

“It’s going to take creativity and a fresh approach. He (O’Rourke) is being very forthright and very frank and very genuine. It presents such an important contrast to Ted Cruz, whose every move is calculated,” Angle contended.

O’Rourke, a three-term congressman, often has taken an unconventional path, stressing his independence and relying heavily on social media to deliver his message.

He has continued that practice in the campaign, using Facebook and Twitter as his primary means to communicate.

In a fundraising solicitation Saturday, O’Rourke said he’d received 19,487 contributions thus far while visiting 22 cities and traveling over 4,000 miles since declaring his candidacy March 31.

O'Rourke said in a statement Monday that he had spoken earlier in the day to Castro, who he referred to as “an extraordinary member of Congress.”

He said he told Castro he understood the decision, adding, “I know that we will continue to work together for a long time to come and I am grateful for that.”

In recent days, Cruz has trumpeted his newly filed legislation that calls for using assets of former Sinaloa Cartel leader Joaquin “El Chapo” Guzman Loera and other drug lords to finance a proposed wall along the border with Mexico. Guzman, who had escaped prison twice in Mexico, recently was extradited to the U.S. to face charges.

The Justice Department declared in January that it would seek forfeiture of over $14 billion in Guzman’s drug profits sent from the U.S. to Mexico. Cruz has cited that figure in promoting his legislation and fundraising, but it is unknown how much of those proceeds remain or how much of that could be retrieved from Mexico.

blambrecht@express-news.net