The meeting in the House is underway now, and they are expected to vote to impeach the president, which would make Trump the first U.S. president to be impeached twice.
U.S. Rep. Joaquin Castro, D-San Antonio, is among nine House Democrats serving as impeachment managers, meaning he will be among those arguing the case before Congress.
READ MORE: Trump impeachment live updates: President Trump on verge of 2nd impeachment after Capitol siege
Trump faces a single charge of "incitement of insurrection" after last week's deadly riot at the U.S. Capitol.
On Tuesday night, Garcia, who was an impeachment manager during the president's first impeachment hearing, explained why she will vote to impeach him again.
"The president of the United States is unhinged, unfit and unstable, or as we say in my district, 'Esta loco el hombre,' to the point where he is willing to tear our democracy down unless he prevails in his quest to overturn the election that he clearly lost," Garcia said.
Garcia added Trump's actions "and those who enable him show that he is unfit to uphold the duties of his office. For the sake of the nation's security, this president must be swiftly removed."
Garcia represents the 29th Congressional District, which includes Houston, Galena Park, Jacinto City, South Houston and Pasadena.
While the first impeachment of Trump last year brought no Republican votes in the House, a small but significant number of leaders and other lawmakers are breaking with the party to join Democrats on Wednesday.
Fact check: No, impeachment itself would not ban Trump from a 2024 presidential run