San Antonio Mayor Julián Castro endorsed state Rep. Pete Gallego this morning in Texas’ 23rd district Democratic runoff.

Gallego is running in a primary runoff against former Rep. Ciro Rodriguez for the right to challenge Rep. Francisco “Quico” Canseco (R) in the fall.

“He is the best candidate in this race to take on Quico Canseco in November, and a proven leader whose steady hand we can count on to serve our community in Congress for years to come,” Castro said.

Strategists agree that name identification was key to Rodriguez’s primary performance. That makes this endorsement significant. Gallego is from Alpine, which is more than a five-hour drive from San Antonio. Political strategists say Gallego’s weakness in the primary was that he is not well-known enough in San Antonio’s Bexar County.

Castro’s twin brother, Julian, is a state Representative who is running to replace retiring Rep. Charlie Gonzalez (D) in Texas’ 20th district. The Castro brothers’ brand is a significant force in Bexar County politics.

Roll Call rates this seat as a Tossup.