NBC MASSAGES POLL RESULTS TO SHOW OBAMA LEADING IN KEY SWING STATES

◼ NBC, soon to be joined by the rest of the media, is swooning over three new polls that all show Obama edging Mitt Romney in the critical swing states of Ohio, Virginia and Florida. - Mike Flynn/Breitbart

The leads are very slim: 4 points in Virginia and Florida and 6 points in Ohio. And, leads have dropped considerably since March. Still, the NBC/Marist poll is the first bit of good news the Obama campaign has had in a few weeks. Too bad NBC had to massage the numbers a bit to get there.

First, all of these polls are of registered voters, rather than adults or likely voters. As we've discussed, that implies a 4% bias for Democrats, which effectively makes the race in these states ties. There are however legitimate reasons to poll only registered voters this early out, so that isn't in any way cheating.

The cheating part comes in how to "weight" the sample to make it fit the pollster assumptions about the electorate. The pollster, ideally, would like the sample to match the partisan make-up he expects in the coming election. If you over- or under-sample one party, this will skew the results. Boy, were the results skewed.