"For a fraction of the cost [of incarcerating Texans with mental health challenges], we could extend health care, especially to the most vulnerable, to make sure they can get mental health care in a clinic instead of a jail, in a clinic instead of the emergency room," he said.

O'Rourke also called for criminal justice reform.

"The war on drugs we've been waging for almost 50 years now has become a war on people, and on some people more than others," he said. "It has produced a prison population that does not look like the population of the United States of America -- it is disproportionately comprised of people of color," he said.

O'Rourke went on to say that people of all races and backgrounds have used and sold drugs, but that punishments and jail sentences have "disproportionately" impacted persons of color.

After his remarks, hundreds of attendees waited in lines to get O'Rourke's "BETO" campaign signs from paid staffers and volunteers.

Emmanuel Daniels, a Texas A&M freshman biology major from Tyler, said O'Rourke's appeals to Republicans, independents and nonvoters resonated with him. "I like how he's a Democrat, but he's not just for Democrats -- he's trying to talk with everybody," he said.