Mr. Castro goes to Washington…

Joaquín Castro, the twin brother of San Antonio Mayor and Democratic National Convention keynote speaker Julián Castro, soundly defeated Republican David Rosa and two third-party candidates on Tuesday night, garnering some 64-percent of the vote.

The 38-year-old Mexican American Harvard-trained attorney and five-term state representative will now represent Texas in the U.S. House of Representatives.

He’ll replace the retiring U.S. Rep. Charlie Gonzalez, D-San Antonio, in District 20. Gonzalez has served since 1999, replacing his father, Henry B. Gonzalez, who held the seat from 1961 to 1999.

“We won this race not only with the support of Democrats but also Republicans and independents,” said Castro.

Castro, considered a rising star of the Democratic Party, is being hailed by political insiders as “the most anticipated Democratic newcomer in Congress come swearing-in time in January.”

The 20th district is about 64 percent Latino and has a majority of Democrat registered voters. (55 percent)