Joaquin Castro

Joaquin served as campaign chair for his identical twin brother, Julián Castro, during his 2020 presidential campaign.

On January 12, 2019, Castro introduced and endorsed his twin brother, former HUD Secretary Julián Castro, at the launch rally of Julián's 2020 presidential campaign.

In February 2019, Castro authored House Joint Resolution 46 to overturn Trump's declaration of a National Emergency Concerning the Southern Border of the United States, under which Trump said he would divert funds from other sources to construct a wall along the U.S.-Mexico border. The bill passed the House by a vote of 245–182 on February 15, and the Senate by a vote of 59–41 on March 15. Trump vetoed the Joint Resolution on March 15.

In August 2019, Castro tweeted the names and employers of 44 San Antonio residents who had given the maximum allowable contribution to Trump's re-election campaign. He said it was "sad to see so many San Antonians" whose "contributions are fueling a campaign of hate that labels Hispanic immigrants as 'invaders'." The information came from publicly available lists published by the Federal Election Commission. The tweet was denounced by Republicans, who said that such a "target list" invites harassment and could even encourage violence.

In 2019, Castro grew a beard so that people could distinguish him from his presidential candidate twin brother Julián Castro.

In 2017, a columnist for the San Antonio Express-News questioned Castro's decision not to enter the 2018 U.S. Senate race against the Republican incumbent Ted Cruz, a presidential candidate in 2016. Bruce Davidson predicted that Castro could have defeated the announced candidate, Beto O'Rourke, representative of Texas's 16th congressional district based in El Paso, for the Democratic senatorial nomination. "Castro is said to be ambitious, but will he ever have a better chance to move up than in the Trump-era against Ted Cruz?," Davidson asked. Davidson added that Texas' other senator, Republican John Cornyn of San Antonio, would have taken advantage of a similar opportunity to run. In 2002, Cornyn, the state's then one-term attorney general, filed to succeed retiring Republican Senator Phil Gramm, while two other Republican hopefuls, Henry Bonilla of Texas's 23rd congressional district and David Dewhurst, the land commissioner and later the lieutenant governor, vacillated and lost their chance to become a senator. Bonilla was defeated for House re-election after redistricting in 2006, and Dewhurst subsequently lost the 2012 Republican runoff election for the Senate to Ted Cruz.

In the 114th Congress, House Democratic Whip Steny Hoyer named Castro a Chief Deputy Whip. During the 2016 presidential election, Castro served as a surrogate for Hillary Clinton's campaign. Castro was selected as chair of the Congressional Hispanic Caucus for the 116th Congress.

Castro is the son of Jesse Guzman and Rosie Castro and the identical twin brother of Julián Castro, the former Mayor of San Antonio and the 16th United States Secretary of Housing and Urban Development in the Cabinet of President Barack Obama; Joaquin is one minute younger than Julián, being born at 2:41AM and 2:40AM respectively. In addition to his work in the Texas Legislature, Castro practiced law in San Antonio. He has also taught as a visiting professor of law at St. Mary's University and as an adjunct professor at Trinity University in San Antonio.

Castro was officially sworn into office on January 3, 2013 becoming a member of the 113th United States Congress. He was chosen as the president of the freshman class of Democrats in the 113th Congress.

In early summer of 2013, Castro became engaged to his girlfriend, Anna Flores. The announcement was made by his twin brother, Julián, on his Facebook page. The couple had a daughter in 2013 and a son in 2016.

However, on November 28, after Charlie Gonzalez of the neighboring 20th District announced his retirement after seven terms, Castro announced his intent to run instead for the 20th District seat. He was unopposed in the Democratic primary, all but assuring him of being the next congressman from this heavily Democratic, Hispanic-majority district. At the 2012 Democratic National Convention, he introduced his brother Julián as keynote speaker. In November 2012, Castro defeated Republican David Rosa 64%-34%. becoming only the fifth person to represent this district since its creation in 1935.

In June 2011, Castro announced that he was running for a seat in the United States House of Representatives in the newly-drawn Texas's 35th congressional district . He was initially set to challenge fellow Democrat and nine-term incumbent Lloyd Doggett, whose home in Austin had been drawn into the district, in the Democratic primary

Castro was born and raised in San Antonio and attended Thomas Jefferson High School. Castro has stated that his interest in public service developed at a young age from watching his parents' involvement in political campaigns and civic causes. His father, Jessie Guzman, is a retired mathematics teacher from the Edgewood Independent School District in the west side of San Antonio, and his mother, Marie "Rosie" Castro, a community activist. Jessie and Rosie never married. Castro's mother named him after Rodolfo Gonzales' poem I Am Joaquin. Castro graduated with honors from Stanford University with a Bachelor of Arts in political science and communications and earned a Juris Doctor with his twin brother at Harvard Law School in Cambridge, Massachusetts. After law school, the two brothers continued together to work for the law firm Akin Gump Strauss Hauer & Feld before starting their own firm in 2005.

Castro ran for Texas's 125th House district in 2002. He defeated incumbent State Representative Arthur Reyna in the Democratic primary 64-36 percent. In the general election, he defeated Republican Nelson Balido, 60-40 percent. He was twenty-eight at the time of his election to the state House. In 2004, he won re-election to a second term unopposed. In 2006, he won re-election to a third term, defeating Republican Nelson Balido, 58%-38%. In 2008, he won re-election to a fourth term unopposed. In 2010, he won re-election to a fifth term, defeating Libertarian Jeffrey Blunt, 78%-22%.

Joaquin Castro (born September 16, 1974) is an American Democratic politician who has served in the United States House of Representatives for Texas' 20th congressional district since 2013. The district includes just over half of his native San Antonio, Texas, as well as some of its nearby suburbs. From 2003 to 2013, Castro was a member of the Texas House of Representatives for District 125. While in the Texas state legislature, Castro served as vice-chair of the Higher Education Committee and was a member of the Judiciary & Civil Jurisprudence Committee. He also previously served on other committees, such as County Affairs, Border & International Affairs, and Juvenile Justice & Family Issues.