The biggest concern for the GOP in the new USA Today/Gallup poll isn't the President's job approval rating (34%, an all-time low for Gallup) and it isn't the 15-point gap in the generic Congressional ballot. It's the question about voter enthusiasm.

When Gallup asked voters "are you more enthusiastic about voting than usual, or less enthusiastic" this November compared to previous elections, 38% of Republicans and Republican leaners said they are "more enthusiastic" while 46% answered they are "less enthusiastic" and 15% said they feel about the same.

On the other hand, 50% of Democrats and Democratic leaners said they are "more enthusiastic" this year than in the past, 37% responded they are "less enthusiastic" and 12% said they feel the same.

Let's stipulate that measuring voter enthusiasm is a tricky business, and doing it six months before an election makes it even more of an academic exercise, but it is valuable insomuch as it gives us a general sense of the mood of voters at this particular point in time.

One bright spot for the GOP is that the Gallup poll showed a 5-point up tick in the number of people expressing "more enthusiasm" for this November versus the last poll taken at the beginning of April. Still, with the outcome of off year midterms driven so much by turnout, the Republicans can't be happy that in the last two polls taken by Gallup close to half of their voters have expressed "less enthusiasm" toward this year's elections.