Cook giveth and Cook taketh away.

Yesterday, the Cook Political Report moved Delaware from Likely Republican to Likely Democrat in light of Christine O'Donnell's primary upset of Rep. Mike Castle. Today, Connecticut goes the other direction, moving to Toss Up from Lean Democrat.

"McMahon has made steady progress against Blumenthal," Cook analyst Jennifer Duffy wrote on Twitter.

Linda McMahon has pulled to within single digits of Dick Blumenthal, who was seen as a shoo-in once Chris Dodd decided not to run for reelection. Obama will be fundraising in Connecticut tonight for Blumenthal, doing two events in a state that was supposed to be a lock for Democrats just months ago.

Joe Biden is on his way to Delaware for Chris Coons. Fire up the Acela, 'cause here he comes!

Next Page