Conservatives are increasingly targeting House Majority Leader Eric Cantor, arguing that he has abandoned conservative principles and protesting his planned meeting with moderate and liberal Republicans. Mr. Cantor, who just a few years ago was seen as a champion for conservatives in the House and a possible candidate to replace House Speaker John A. Boehner, now is viewed with suspicion, said Rep. Dana Rohrabacher, California Republican. “I think that Boehner can survive the discontent that the tea party and the more conservative element of the Republican Party has, but I don’t think that is true of Cantor,” Mr. Rohrabacher told...