(1) Black voters came out for her in droves in 2000. Black voters will now be less than fired up about her. Many black voters feel that she sabotaged Carl McCall's gubernatorial race. Her Clinton administration crony Andrew Cuomo spent months dragging McCall through the mud before dropping out of the Democratic primary. Then her other Clinton administration crony Terry McAuliffe refused to help McCall and spent big on McAuliffe's white friend Bill McBride in Florida, who was trounced almost as solidly as McCall was.
(2) She was being sent as a Democrat to a Democrat-controlled Senate. If the Republican party still controls the Senate in 2006, the case can be made to independents and some Democrats that NY needs a moderate Republican in Washington to further the state's interests.
(3) She was elected before 9/11. Pataki won statewide mostly because he was perceived as having responded correctly to 9/11. Clinton's obstructionism on homeland security will come back to haunt her.
If the right Republican can be found, she will prove to be vulnerable in ways she wasn't in 2000.
Many of us (me included) didn't think she'd win in NY in 2000, but she did. This woman is evil, clever, and worst of all, patient. By the time she runs for president, she's counting on everybody forgetting the trail of sleaze she left behind after she left the White House.
I do think it'll be challenging for her to win a national election, simply because 40-45% of the electorate will never, ever support her. But if we don't seriously challenge her with a good candidate AND continue to educate people about her record, we could be in for the shock of our lives.