Thus far, interest in this year’s midterm elections is in almost inverse proportion to their importance. The most important question is whether the Republicans will gain control of the Senate while retaining their majority in the House. That could make Congress still more belligerent toward the president. It would not only continue to block progress on pressing national needs but also prevent him from shoring up the progressive faction on the Supreme Court against what a possible Republican successor would do.

Also uncertain is to what extent the Democrats can reverse the enormous gains the Republicans made in 2010, when they took over both the governorships and the legislatures of twelve formerly Democratic states. They now control twenty-six states, which has had major substantive effects on national policy. For example, twenty Republican-dominated states have refused to expand Medicaid coverage to their poorest citizens or to set up their own health insurance exchanges under the Affordable Care Act.

The outcomes in the state elections will affect the extent to which redistricting will result in an even more unrepresentative system and exacerbate gridlock and hyperpartisanship in Washington. As of now, the turnout this November is predicted to be uncommonly low, even for midterms, which traditionally attract fewer voters than do presidential elections. Midterm voters are older, whiter, and, since they include fewer and fewer veterans of the New Deal era, over time they have come to represent more conservative values than the voters in presidential contests. The political analyst Charlie Cook says:

In effect, seniors, who have always had a disproportionate influence in midterms because they have a higher participating rate than any other group, have switched sides and are more conservative than before. As this has happened, the difference between midterm and presidential electorates has widened.

We have in effect two different electorates.

Republicans have been remarkably successful in blocking bills supported by Obama, and this in turn has helped convince voters that his accomplishments are meager. Frustration with the gridlock in Washington and feelings of discouragement about the future have led to a particularly sour electorate, which also takes a dim view of the Republican Congress. (In recent polling, no more than 19 percent approved of it.) The sour mood could well affect the turnout; and a small number of voters could determine how the country is governed for the next two years.

With the president’s job approval dropping to 40 percent, according to the latest NBC/Wall Street Journal poll (other polls were slightly higher), Republicans are trying to identify his party’s candidates with him. And since for the first time his rating for likability is below 50 percent, the president now has less to fall back on. It’s often difficult for politicians of the president’s party…