San Antonio Representative Joaquin Castro tells Texas Monthly that he has decided against a run for the U.S. Senate against incumbent Republican John Cornyn. Castro, 44, said he feels that he can accomplish more in the majority party in the U.S. House than running in “the fight of my life” for a seat in the Republican-controlled Senate.

“This place is dysfunctional as it is,” he said of Congress. He said that he’s in a better position to effect change in his current role. The announcement, first reported in the San Antonio Express-News, comes a week after another Democrat, M.J. Hegar, announced her candidacy against the well-funded Cornyn. Castro currently serves on the House Intelligence Committee and several subcommittees related to foreign affairs and anti-terrorism. He also is chairman of the Congressional Hispanic Caucus.

Castro told me that he “thought long and hard” about challenging Cornyn who is viewed as vulnerable in the wake of last year’s U.S. Senate race in which Democrat Beto O’Rourke came within three points of upsetting  Ted Cruz. O’Rourke has since announced his intent to run for president. Castro is the identical twin brother of Julián Castro, who has also announced his candidacy for president.

Hispanic voters, in particular, have invested a lot of hope in the Castro brothers. But there seems to be a growing fatigue on what’s seen as the overly cautious nature of both brothers. To be fair, the Castros have argued that their caution has more to do with pragmatism than a fear of losing.

Earlier this year, several sources close to Joaquin Castro told me he was “all but certain” to enter the race against Cornyn. But several longtime Democratic political operatives warned that he may change his mind given his actions in the past.

Cornyn’s campaign was quick to tie Castro’s decision to U.S. Senate Minority Leader Chuck Schumer, who was reported to have favored Hegar over Castro. His campaign implied that ethnicity was a factor in Schumer preferring the white Hegar over the Hispanic Castro.

“Despite Rep. Castro saying he was all but certain to run, Chuck Schumer and DC Democrats had other ideas,” the Cornyn campaign said in a written statement. “Chuck Schumer recruited and picked MJ ‘Hollywood’ Hegar instead, pushing Castro aside and ignoring the Texas Latino grassroots. Hollywood Hegar may have the support of the New York and California elites but she has none in Texas. Shame on Chuck Schumer and DC Democrats for forcing a high-profile Hispanic leader out of the Senate race.”

Several prominent Hispanic Democrats signed a petition to recruit Joaquin to run. They include Congresswoman Veronica Escobar, Congressman Filemon Vela, Congresswoman Sylvia Garcia, Congressman Vicente Gonzalez, Texas State Representative Gina Hinojosa, Texas State Representative Celia Israel, Texas State Representative Mary Gonzalez, Texas State Representative Lina Ortega, and Former Texas State Senator and Lt. Governor Candidate Leticia Van de Putte.

Cornyn has been saying for months that he will not underestimate any opponent given the results of last year’s election involving Cruz. Cornyn has more than $7 million cash on hand, more than any incumbent Senate candidate and has actively engaged Hegar since her announcement last week.