Several bloggers are pointing out that Cantor's comments could constitute a felony (a violation of the Logan Act) and in fact Cantor himself has made similar accusations against other members of Congress who have had independent interactions with foreign leaders. Others in the blogosphere are even accusing Cantor of treason and calling for his impeachment. I think he should definitely be given some sanctions for pledging to a foreign leader that he would serve as a check on the White House, but I'm not holding my breath.
OpEd News: Cantor, Thy Name is Traitor by Saman Mohammadi
Salon: Eric Cantor's Pledge of Alleigance
Laura Rozen: Before Clinton meeting, Cantor's one-on-one with Bibi