The May 07 debate was the genesis for me. As a college student I had voted for Bush in 00 and 04. During the four years in between I was an active fan of Increasing U.S hegemony and democracy promotion... basicly a neo-con. I supported the war in Iraq, not because of al queda or WMDs, but because I thought having a large force in Iraq would be in our best interest. :doh:
Over the next couple of years I realized, far too late, that being in Iraq was not in our interests and I was totally wrong. I had gone into the debate interested in supporting Giuliani, but Paul standing up to Giuliani impressed me and educated me by filling in the gaps of my understanding about how America should behave in the world. Once I learned about his voting record and pro-life stance I was sold.
Edit to add: you know as I look back the big thing that helped me come around was how Paul pointed out the platform Bush ran on in 2000. That made me feel like I was coming full circle back to where I had started rather than veering off to some new position. Although in actuality I have ended up in a place fairly far from where I was as an 18 yo voting for bush.