In an appearance at the Reagan Library Saturday night, Sen. Rand Paul (R-Ky.) took a dig at John McCain over the Arizona senator's recent visit to Syria.

"I'm very worried about getting involved in a new war in Syria," Paul said, because while President Bashar al-Assad is "a bad guy," there's al-Qaeda and al-Nusra (an al-Qaeda linked Islamist group) on the other side.

"They say 'there are some pro-Western people, and we're going to vet them,' well apparently we had a senator over there who had his picture taken with some kidnappers, so I don't know how good a job we're doing vetting those who are going to get the arms," he said, to applause.