Despite what you see and read in the MSM, Both Hillary and Rudy are a long way from their parties nominations. Sure, it looks very good for Hillary, but it's also easy to imagine a precipitous fall.
How much of Hillary's lead is based upon the belief that she is the inevitable nominee?
According to Election Central Obama is effectively tied with Hillary in Iowa. Hillary losing Iowa could be catastrophic to her campaign. Not only would it be a huge boost to Obama or Edwards with a huge media circus (driven as much by a Hillary loss as a win by Obama or Edwards) but a devastating blow to Hillary's image as inevitable winner going into New Hampshire. If The Iowa boost is enough to cost Hillary New Hampshire than she's going into South Carolina with NO WINS and does anyone think Hillary will win in South Carolina?
This, by the way, is why Hillary would not withdraw from the January 15 Michigan Primary.
Don't let anyone tell you that Hillary has this sewn up. Hillary doesn't believe it and you should either.
And you can make the same analysis of the GOP race with Rudy behind Romney in both Iowa and New Hampshire.