State Sen. Dan Patrick is no stranger to over-the-top statements about immigrants and immigration. The Houston-area Republican, who is the GOP’s leading candidate for lieutenant governor, told a group in 2006 that immigrants are “bringing Third World diseases with them,” referencing “tuberculosis, malaria, polio and leprosy.” (A top official at the Department of State Health Services had to slap that down, pointing out, for instance, there hasn’t been a case of polio in decades). When asked to address the issue of immigration at a forum of leading business groups during this campaign, Patrick chose to talk about violent crime, as...