LEWISTON — A Mexican-American member of Congress from Texas will serve as the keynote speaker of the Maine Democratic Party’s convention at The Androscoggin Bank Colisée next month.

Rep. Joaquin Castro, a 43-year-old Democrat, is “an incredible champion for middle-class Americans in Congress, and we are excited to have him join us in Lewiston for our convention,” state party leader Phil Bartlett said in a prepared statement.

The three-day convention is slated to start Friday, May 18. Castro is scheduled to speak at 4 p.m. Saturday, shortly before the gathering ends for the day.

Democratic candidates plan to speak both Friday evening and earlier Saturday afternoon.

Organizers anticipate more than 1,000 Democrats coming together from across the state for the convention, which serves mostly as a way to ramp up excitement among loyalists for the general election campaign this year.

The only formal role for delegates is to pick state committee members, something of interest to party insiders, but few others.

Among those expected to address the convention are the seven Democrats competing in a June 12 primary for governor and four Democrats vying in the primary for the party’s backing to take on U.S. Rep. Bruce Poliquin, a two-term 2nd District Republican.

Castro has become a national figure in part because of his active role on the House Intelligence Committee, where he has opposed GOP efforts to stymie an investigation into Russian meddling in the 2016 presidential election.

As the chief deputy whip for the Democratic minority in the House, Castro is among the party’s leaders in the House, which mostly consists of much older representatives.

Castro is a graduate of Stanford University and Harvard Law School. He practiced law in San Antonio while serving in the Texas Legislature.

First elected to the House in 2012, Castro “has spent his entire career making sure that all Americans have a fair shot at success and equal opportunity to build better lives for themselves and their families,” Bartlett said.