The Senator Thing
Here's an interesting article
on how senators have a tough time making the jump to the presidency. The article starts out with a focus on the ridiculous talk about Barack Obama. This part drew a chortle:"The Senate historically has not been a great place from which to run for president," said former senator Bob Graham (D-Fla.), who personally learned the lesson in 2004. "Senator Obama might feel he would be better off to run while he has not been tainted by an excessive period in the Senate."
I don't think that less experience as a senator is likely to make one a stronger candidate. The article does note that the two frontrunners for 2008 are both in the Senate: Hillary Clinton and John McCain. Obviously if both of them manage to be nominated, the curse of the Senate will only affect one of them.