How different would conditions be today economically and politically if unemployment were 7 percent instead of its current 8.2 percent? For one thing, some two million unemployed workers would have jobs, and the rate of economic growth would be comfortably above 2 percent, instead of below that pace. This scenario could have been possible if federal aid to states had been bolstered, saving hundreds of thousands of public-sector jobs.

Mr. Obama can make a convincing case that his policies — especially the stimulus and auto industry rescue — helped cushioned the effects of the recession he inherited, which pushed the jobless rate from an already elevated 7.8 percent in January 2009 to 10 percent by October 2009. It has come down, more or less, steadily since then. But it is still higher than when he took office — a point that Mitt Romney and Congressional Republicans have seized upon as evidence of failed policies.

Actually, it was the Republicans’ relentless opposition to constructive policies that has kept unemployment high, from their resistance to the 2009 stimulus to their blockage of Mr. Obama’s proposed $450 billion jobs bill in late 2011. Federal aid to states was a mainstay of both of those efforts. As the stimulus ended and further aid was delayed and denied, the effect on state budgets — and on jobs — has been catastrophic.

A recent analysis by the Economic Policy Institute shows that the loss of public-sector jobs, largely because of state budget cuts, has been the biggest hit to job growth over the past three years.