San Antonio Mayor Julian Castro may find himself in the hot seat Tuesday at the invitation of the U.S. House Judiciary Committee, where he has been asked to testify about his support of comprehensive immigration reform.

Castro said he finds early bipartisan support in the U.S. Senate encouraging.

“My message to Congress will be to take advantage of that, to roll up your sleeves,” Castro said.

However, Castro said he is aware hard line opposition remains.

“It’s unfortunate that before there’s actual legislation on the table, some folks have dismissed it out of hand,” Castro said.

No longer chair -- but a member of the House Judiciary Committee -- Rep. Lamar Smith of San Antonio, R-Dist. 21, said last week, “Granting amnesty compounds the problem, encouraging illegal immigration.”

Castro said actually several obstacles need to be overcome on the path to citizenship.

“They pay a fine. They learn English. They get to the back of the line and pay taxes,” Castro said.

The mayor said more border security, employer penalties, and a guest worker plan also are included in a bipartisan framework.

He also said America is denied the skills of talented young people who entered the U.S. illegally as children with their parents

"(They) could be adding to the bottom line of the United States," he said. "Instead, they’re adding to another country’s bottom line.”

Castro said immigration of many nationalities has been treated as a “political piñata” for generations.

As the mayor of the largest Texas city closest to the Rio Grande, Castro said he tell Congress, “This is the moment. This is the opportunity for Congress to show the United States that it can still work, that it can still get things done.”