I might take that pledge if not for McCain. I think I am going to have to start a support group, if one doesn't already exist, for Democrats who love McCain.
Think about the Supreme Court...
Also think about an all-but-guaranteed Democratic majority in the Senate.
McCain couldn't nominate judges as conservative as Roberts or Alito, even if he wanted to.
I won't take the pledge: I have serious problems voting for another Clinton or another Bush. I might vote for Hillary depending on whom she's running against. However, I could live with McCain and if he ends up being the Republican nominee I just might vote for him. If Bloomberg runs and Hillary is the dem nominee, I might vote for him.
The problem with Hillary is that she's so polarizing and so hated by 50% of the country that she couldn't do anything in office and she would gauruntee the Republicans a good 2010.