Party ID and the polls

Michael Barone:

What's with the polls?

In 2004, the electorate that went to the polls or voted absentee was, according to the adjusted NEP exit poll, 37 percent Democratic and 37 percent Republican. In party identification, it was the most Republican electorate since George Gallup conducted his first random sample poll in October 1935.

But most recent national polls show Democrats with an advantage in party identification in the vicinity of 5 percent to 12 percent. Party identification usually changes slowly. Historically, voters have switched from candidates of one party to candidates of the other more readily than they have changed their party identification.

Over time, big changes in party ID can and do occur. When I started in the polling business, in 1974, national party identification was almost 50 percent Democratic and not much more than 25 percent Republican.

Since then, Democratic party ID has fallen, particularly in the South, where many voters who considered themselves Democrats found themselves voting Republican for president and, increasingly in the 1980s and 1990s, for other offices, as well.

Republican party ID has increased. But that's a process that took decades. If you could go back in history and conduct polls, I don't think you'd find any, and certainly not many, two-year periods when the balance in party identification shifted from even to having one party 12 percent ahead of the other.

...

Fewer people vote in off-year elections than in presidential years. In 2002, 75 million people voted. In 2004, 122 million did. My hunch is that people who identify themselves as independents are substantially less likely to vote this year than people who identify as Republicans or Democrats -- which would be good news for Republicans, since independents give Bush low job ratings. Another hunch is that the Republican turnout apparatus, with which the Democrats haven't yet caught up, will boost Republican turnout as it did in 2004, and that the resulting electorate will be more evenly divided in party identification than the electorates shown in most of the public polls.

Serious pollsters concede that there are some problems with polling. Americans have fewer landline phones than they used to, and the random digit dialing most pollsters use does not include cell-phone numbers. Larger and larger percentages of those called are declining to be interviewed.

...

I have not heard a convincing argument for the over weighting of Democrats in most polls, but that is certainly the basis for the negative predictions for Republicans. The assumptions also seem to move closer to Republicans the closer we get to the election. Just look at the recent Zogby poll results in DeLay's old district. This was one that the Democrats were already counting on. If the Democrats do win that district it will not be because the voters have become Democrats or even favor the Democrat candidate. It will be because the Democrats were successful at thwarting democracy by keeping the Republican candidate off the ballot.