Obama no doubt thinks that the only way to make the last years of his presidency productive is to hold the Senate against the odds and, through the shock value of that outcome, force a change of behavior among the Republicans.Does either of those two predictions seem probable? The first looks extremely unlikely, I don't see House Republicans being able to go along with the President and Harry Reid, even if somehow they wanted to.
Republicans no doubt believe that if they take back the Senate and thus control both chambers of Congress next year, the president will have no choice but to begin to deal with them differently.
In the second scenario, I expect the President to veto everything passed by a GOP Congress and spend his time on foreign affairs and fund-raising. Prognosis: two more years of gridlock, whatever happens in November.