Lauro was born in Beaumont, Texas, on May 20th, 1933, to Manuel Cruz and Margarita Menchaca Cruz. They moved to Houston with Lauro 6 months later. He attended both a Lutheran elementary school and a public high school in Houston. He enlisted in the United States Marine Corps during the Korean War and during that time obtained his GED. He arrived back in Houston and applied for a job as a bus driver for the Metropolitan Transit Authority of Harris County. Lauro said, "…there was a lot of resistance…." He felt the transit authority did everything they could to "bust him out" during training. He was successful though and became the first Mexican-American to drive a bus in Harris County. He married Clarice at Trinity Lutheran Church and subsequently enrolled in the University of Houston where earned his BA in Political Science. Afterwards, he attended law school at South Texas College of Law while at the same time operating a grocery store in Precinct 1 in downtown Houston. He later became the Precinct Chairman.
Lauro ran for and was elected to the Texas State House of Representatives for District 115 in Houston and served three terms, from 1967 to 1971. He was the first Mexican-American legislator to be elected in Harris County since 1836, when Lorenzo De Zavala was elected Vice-President of the Republic of Texas. Lauro never forgot his participation in the 1966 march to Austin for farm workers' rights. He helped author and co-sponsored the effort to pass the first state minimum wage bill, passed the migrant transportation bill, and later passed the state act regulating hazardous substances in Texas. Throughout his political career, he worked tirelessly for minorities and for equal pay and rights for farm and migrant workers.
After an unsuccessful run for State Treasurer, he went to work in 1972 as the only Mexican-American special assistant to Texas Governor, Dolph Briscoe. In 1973, he received the National Benito Juarez-Lincoln Award for his contribution to the progress of Mexican Americans in the United States. In 1974, he became the Executive Director of the Greater South Texas Cultural Basin Commission. Following that, he headed the Texas Good Neighbor Commission whose goal was to improve relations between Texas and Mexico, address the needs of migrant workers and solve issues among Mexican Americans living in Texas. After his service in office, he became one of the first independent Hispanic lobbyists in Texas. He created and taught the Innovation 88 Leadership Program at the Lyndon B. Johnson School of Public Affairs at the University of Texas. The classes were aimed at helping upcoming leaders in the late 80's and early 90's learn about the Mexican-American experience in Texas and about how politics really works behind the scenes. Lauro served as President of the International Hospitality Council in Austin which is a State Department affiliated program that is now named Global Austin. Throughout his life, Lauro provided a voice for those who had none.
Lauro and Clarice had been married to each other for over 61 years and were active, faithful members of the Lutheran Church for their entire married life.