He promised to veto McCain Feingold, but he signed it into law.
When did he make that promise? I don't remember it.
I suspect that some Republicans may have gone along with it on the theory that the USSC would strike down the bad parts leaving in place the increased personal contribution limits. Dangerous game, given the USSC.
Did he promise to veto? I don't remember that. I thought he sort of tiptoed around it in 2000. As his veto record shows, he's deferential to the Congress to a fault.