I just finished reading an article on Howard Dean on the Guardian Unlimited site. Dean being the frontrunner for the Democrats means he's getting more press than the others. I think General Clark is the only one with any real chance of beating Bush, but Dean is generating a lot more excitement.
The funny thing is that "liberal" is such a dirty word in America that an American "liberal" like Dean is closer to a conservative in many other countries. With the exception of a few of the more fundamentalist Members of Parliament in the Reform/Alliance/conservative party(ies) most of the right in Canada would be centre in the States. Preston Manning for example would probably be considered a Red Republican. (Or Blue Republican because they switch the colour codes down there).