It’s still a bit early, so the Republican result is not certain, but if Romney should lose it will reinforce the impression that, having tried to buy his way to a victory through massive ad buys (3x McCain’s advertising), he could not persuade most voters to bring themselves to vote for the man even though they probably saw his ads more often than almost anyone else’s in the last week.  There will be a temptation in the pro-Romney conservative media to blame Huckabee for a Romney loss, because he seems to have pulled away many of the same kinds of voters that backed Romney, but Giuliani’s role in siphoning off likely McCain voters will have to be kept in mind.  Huckabee’s result will hurt him, but he has a future at least through next week.  Giuliani has little reason to continue.  Certainly, Giuliani can help the establishment and keep holding down McCain’s vote by pulling away supporters, but so long as Huckabee ties up a sizeable part of the conservative vote it won’t do Romney any good.  Nothing compels Romney to withdraw, but he has few likely prospects for success next week if he loses tonight.