We know that party identification moves over time — sometimes in very short periods of time, just like other political variables. Generally, if there is a political tide toward either of the two major parties, all questions we ask that are of a political nature will move in that direction. This includes the ballot, job approval, party identification, among others.

So, it would not be surprising to find that if Barack Obama is enjoying a surge in popularity in any given state, that surge will show up on the ballot question, on his job approval measure, and on the measure of party identification. So, data showing that Obama is ahead on the ballot in a specific state poll and that Democrats have a higher-than-expected representation on the party identification question, are basically just reflecting two measures of the same underlying phenomenon. …

Basically, if an observer is concerned about a poll’s results, that observer should skip over the party identification question and just look at the ballot directly. In other words, cut to the chase. Don’t bother with party identification sample numbers. Look directly at the ballot.