Having been named "Legislator of the Year" "Best of the House" or "Champion" over a dozen times by numerous statewide organizations, no other member has passed more legislation out of the House in a single session in history. Capitol Inside called him a "House Bill Machine" and "a one-person assembly line for legislation." Recently appointed as the Chair of the House Committee on Homeland Security & Public Safety and as a member of the House Committee on State Affairs, Guillen has a long history of leadership roles in the Texas Legislature, including having served in leadership positions in all four administrations that he has served under, and having been Vice-Chair of the powerful Appropriations Committee by age 29.

Guillen has been a staunch advocate for creating jobs, cutting taxes and red tape, for reducing over testing, for working to keep our families and communities safe, for maintaining Texas' position as an energy leader, for improving our roads and infrastructure, for protecting property rights and our rural way-of-life, for boosting our state's role in supporting veteran families, and for fostering greater efficiency and transparency in government.

Known for his hard work and relentless efforts for South Texas families, Guillen hosts a seasonal Dairy Queen Listening Tour in every county in the district, a Weekly Coffee during legislative sessions, and a Virtual Community Summit to be available and accessible to constituents, and to keep them informed. He also hosts a Student Legislative Session, and a Legislative Internship Program to educate and inspire our youth and young adults.

He and his wife, Dalinda, have two daughters, Cinco Demi and Viva Bonita.