Former Florida Gov. Jeb Bush (R) on Friday suggested that Republicans were outsourcing their "principles and convictions" by signing Grover Norquist's pledge to never raise taxes.

During a House Budget Committee hearing, Rep. Chris Van Hollen (D-MD) asked the former governor if he agreed with the Americans for Tax Reform pledge.

"No," Bush said, shaking his head. "OK, so I ran for office three times. The pledge was presented to me three times. I never signed the pledge. I cut taxes every year I was governor."

"I don't believe you outsource your principles and convictions to people," he added. "I respect Grover's political involvement. He has it every right to do it, but I never signed any pledge."

Since introducing the pledge in 1986, Norquist has been remarkably successful at getting signatures from Republicans. Only six of the 242 Republicans serving in the House today have not signed on.

But things could be changing this year as 25 of the candidates promoted by the National Republican Congressional Committee have so far refused to add their names to the list.

"For what it's worth, I don't necessarily see this as evidence of moderation," MSNBC's Steve Benen wrote on Tuesday. "On the contrary, many, if not all, of those who are rejecting Norquist's project appear to be very much in line with his party's anti-tax orthodoxy. They're balking, not because they intend to support tax increases, but because some are open to trading away tax credits, some don't like taking orders from D.C. lobbying groups, and some are just anti-pledge in general."

Watch this video from C-SPAN, broadcast June 1, 2012.

(h/t: Talking Points Memo)