The best way of looking at the midterm elections is to understand that the Democrats have huge disadvantages that threaten to overwhelm the fact that people dislike the Republicans intensely and narrowly prefer to have the Democrats in control of government. It’s very unlikely that more people will show up to the polls to vote for Republican candidates than for Democratic ones. But that’s not how the elections will be decided.
Even if the Democrats do an excellent job of voter turnout and erase the enthusiasm gap, they still are unlikely to have a particularly good night. Picking up seats in the Senate is out of the question, and regaining control of the House is highly unlikely.
These midterms are really about mitigating potential damage and positioning the party to win control of the presidency and both chambers of Congress (with a supermajority in the Senate, hopefully) after the 2016 elections. If the Democrats can pick up a handful of House seats and limit the damage in the Senate to the loss of just one-to-four seats, they’ll have a real shot at having enough power in 2017 to enact another wave of progressive legislation. That’s really what we all ought to be focused on.