D.J. Drummond, at Wizbang, explains Obama’s miraculous recovery in Gallup’s Polls.

Obama’s support goes up and down, but the Liberal and Moderate Democrat support for Obama has been steady all of September. Odd, isn’t it? And support for Obama among Conservative Democrats went down four points in the last week, even though his overall support is supposed to have gone up four points. How to figure that?

Perhaps it’s in the Independents. …

Hmmm, again. Obama gained support among Independents in the last month, but he actually lost two points among Independents in the last week. So that 4 point gain overall is still a mystery.

Nothing to do, then, but look at the Republicans. It would really be something if he’s improving support from GOP voters:

Ouch. Obama lost six points among Liberal and Moderate Republicans in the past week.

Conservative Republican support for Obama …

No change there in the past week.

Taken altogether, there is no group of political identification where Obama’s support has increased in the past week. Mathematically, therefore, there is only one way in which Gallup could show an increase in Obama’s overall support, when none of the party identification groups showed improvement for him.

Before I explain that possibility, I want to look at John McCain’s support by specific party identification groups. The man, according to Gallup, lost four points of overall support in the past week,

Conservative Republican support for McCain…

Interesting. McCain’s support among Conservative Republicans went up a point in the last week.

Wow, McCain’s support from Liberal and Moderate Republicans climbed by seven points in the past week, and yet we are told his overall support fell by four points? That is very odd, wouldn’t you say? It must have been the Independents, perhaps?

Independent support for McCain …

Stranger and stranger, McCain’s support among Independents went up by four points in the past week, just as his support from Republicans increased, yet we are told his overall support went down by four. Very hard to explain that using the math most of us learned in school, isn’t it? Well, there’s just one place left to look. Maybe somehow McCain used to have significant support among Democrats, but lost it? Let’s find out:

Conservative Democrat support for McCain …

Hmpf. Once again, a group where support for McCain went up (3%), but the overall says he went down.

Moderate Democrat support for McCain …

Steady there, so that one does not explain it.

Liberal Democrat support for McCain…

It’s only a point, but again we see McCain’s numbers in this group went up.

So, put it all together, and in the past week Obama has stayed steady or lost support in every party identification group, yet Gallup says his overall support went up four points. And McCain stayed steady or went up in every party identification group, yet we are supposed to accept the claim that his overall support went down by four points? Anyone have an answer for how that is even possible?

Well, actually I do. There is one, and only one, possible way that such a thing can happen mathematically. And that way, is that Gallup made major changes to the political affiliation weighting from the last week to now. Gallup has significantly increased the proportional weight of Democrat response and reduced the weight of Republican response.

Read the whole thing.