Marco Rubio once looked like the Republican savior over immigration. Now, to some conservatives, he seems as trustworthy as a door-to-door salesman. From the right-wing talk-show hosts to local activists at town halls, many conservatives say they’re upset that Rubio’s talk and deeds conflict over comprehensive immigration reform. “The problem is he sold this based on talking points,” said Jason Hoyt, an Orlando tea party activist, summing up the discomfort many conservatives have with the Florida Republican senator. “He had four or five talking points, which sounded pretty good,” Hoyt said. “But then we saw the bill, and it was...