Not exactly a burn as much as a giant middle finger, but Republican candidate Donald Trump refused to take the pledge to not run a campaign against whoever gets the Republican nomination. The only way, he said, he wouldn't run against the Republican nominee were if he himself won the nomination.
Not so much of a burn as an embarrassing moment for Scott Walker. Seems that he can't differentiate between a country that is our ally and an entire region that, for the most part, has been the enemy of the United States. He said, "You look at Egypt? Probably the best relationship we’ve had in Israel, at least in my lifetime."