San Antonio Rep. Joaquin Castro announced Monday he will not challenge Sen. Cruz in the upcoming Senate race.

Castro has been pushing off his public announcement since February. As of last week, he was reportedly undecided.

The Washington Post reported Monday:

Castro, who represents San Antonio in Congress, made his decision over the weekend and began informing close supporters and donors on Sunday, according to people familiar with his decision. The announcement caps several months of deliberations by the third-term lawmaker, whose twin brother, Julián Castro, is the former secretary of housing and urban development and is mulling a possible 2020 presidential campaign.

While Joaquin Castro says he is not considering a Senate run now, he isn’t entirely ruling out such a campaign down the road. For now, Castro is preparing to run for reelection to his House seat but realizes that political developments could change his decision, said an aide familiar with the congressman’s thinking who spoke on the condition of anonymity to talk frankly about political strategy.

Castro said he won’t rule out a senate run in the future.

Beto O’Rourke, Democratic Congressman from El Paso announced his candidacy at the end of March. O’Rourke is not a traditional Democrat. He’s promised to limit his service in the upper chamber to two terms if elected.

Castro’s decision to sit out the 2018 Senate race is a wise one. Texas-wide elections are costly and traversing the huge state tiresome.

The WaPo continued:

By staying out of the race — at least for now — Castro avoids a potentially costly primary fight with O’Rourke, a representative from El Paso who jumped into the Senate race in March. Whichever Democrat emerges as the party nominee next year faces daunting political history: Not since Bob Bullock was reelected lieutenant governor in 1994 has a Democrat won statewide office in Texas.

Adding to the Democratic Party’s challenge, statewide campaigns in Texas require a presence in 20 media markets, including three of the most expensive in the country -— meaning that a competitive race against Cruz would be a multimillion dollar affair at a time when Democrats will be defending 25 seats across the country.

“I wouldn’t count on any support from the DSCC, because they’ve got their hands full with trying to reelect 25 Democrats,” Castro said at a recent Washington Post Live event when asked about a possible Senate run, referring to the Democratic Senatorial Campaign Committee.

Castro predicted that a Senate race against Cruz would cost “tens of millions of dollars,” before adding later: “I think I could raise it, and Ted Cruz would help me raise it.”

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