Back-to-back surprises have given Democrats a burst of optimism that they can hold on to control of the Senate, a goal that seemed to be slipping from reach just weeks ago.
Republicans and Democrats alike were surprised that Maine Sen. Olympia Snowe has decided to retire and that former Nebraska Sen. Bob Kerrey has reversed course and decided to run for the Senate again.
That puts two seats Democrats were prepared to write off in November back into play, at least for now.
Those developments, combined with an improving economy and President Barack Obama's higher standing in polls, have some sensing a shift in the environment -- and in Democrats' favor.
Still, Democrats must overcome challenges to compete aggressively in both Maine and Nebraska.