Republicans Becoming Independents?

Democratic pollster Stan Greenberg claims the lack of Republicans in recent polls is due to the Republicans becoming independents.That's the idea generally floated on the left to explain that the samples are fine. There are problems with it.

1. Republican registration is increasing compared to Democratic in many states. What you're seeing here, e.g. a drop from 37% to 28% in Ohio, implies that 25% of the people left the party. You'd think you'd see some drop in Republican registration would show up.

2. This is true in California, but Democrats are also declining and the Republican drop is 1% of the total from 2008 from 31% to 30%. It's not 9%. Drops that sharp don't happen.

3. They are voting Democratic. We can take the 2008 Virginia voting and move the people that were Republicans and Democrats but are now independents according to Greenberg using this CBS/New York Times poll. If they voted 92%-8% Republican, Romney would lead 56%-44% with independents. Yet he still trails by one in this CBS News poll. So they'd not only having to be leaving the Republican party, but half of these McCain voters are now voting Obama. Anyone have the sense that this many Republicans have moved to the left in the last 4 years and are now voting Obama?

4. If they didn't leave in 2010, when Republican party approval ratings were much lower with Republicans why leave now that you've gotten all the people you wanted in there elected?

It's very possible that a small percentage have become independents, but nothing this massive. They can't say that Republicans aren't planning to vote, since their polls generally include 85-95% of the registered voters in their sample. And in most polls, Republicans do better with likely voters. The polls simply are missing these Republicans.