So what happened to that ten point GOP lead?

Ummmmm....

Last week, Gallup's generic-ballot tracking poll showed Republicans leading Democrats by 10, 51% to 41%. It was billed as the GOP's biggest Gallup lead in the history of humanity, and the results generated massive media attention, including a stand-alone Washington Post piece on page A2. It was iron-clad evidence, we were told, of impending Democratic doom.

I strongly recommended caution -- Gallup's generic-ballot tracking poll has been erratic and unreliable. Both parties had built up big leads in recent months, only to see them quickly disappear, for no apparent reason. I made the case that inconsistent polls with bizarre swings are necessarily suspect, but the media had its narrative -- the GOP tsunami is coming -- and couldn't be bothered to consider whether the Gallup poll had merit.

Wouldn't you know it, a week later, that massive, unprecedented, world-changing lead Republicans enjoyed is gone. The new Gallup numbers show the GOP losing five points and Dems gaining five points, leaving the parties tied at 46%. Is there any coherent rationale to explain a 10-point swing in Dems' favor over the last week? Of course not.

Just to be perfectly clear, I don't consider this evidence of a surge in Democratic support, and Dems who rejoice at this poll are making the same mistake Republicans and reporters made last week. The point is Gallup's generic-ballot tracking poll just isn't telling us anything useful, no matter which party likes the results in any given week.