McCain as front runner? You mean republican front runner right?
I haven't seen a final presidential poll till now.
And i cannot imagine Huckabee as running mate of McCain

Even though Huckabee would probably come up as a hardworking conservative hand to McCain which he can do with with his centralist positions, but the way Huckabee is fighting the campaign and refusing to acknowledge McCain, its highly unlikely McCain is too pleased
As far as democrats go, its now or never for Clinton. I saw the Howard Dean interview and on late edition and he was atleast categoric that the electorate will elect the nominee and not some super delegate. So for that to happen for Clinton, she has to win Texas and Ohio today(in a big way at that) else its game over for her.
And she is anyway rattled with her recent appearances in debates. She is actually getting booed with some of her remarks

Remember the jhon Stewart, Daily Show spoof on the use of word to describe the anti sematic leaders backing to the Obama campaign. Reject vs Denounce (
Denounce v. Reject - First Read - msnbc.com)

Clinton campaign has reached heights of foolishness

and in all that she still manages to make a mess of it all.