I meant to blog this a couple days ago but I’ve been “busy” …
Jim Geraghty at National Review’s Campaign Spot nicely laid out the argument why party ID in matters in polling. This is a hotly contested issue especially since some pollsters weight their polls based on party identification and some do not. Geraghty also does a great job laying out the mischaracterization many in the media make to defend this practice. The don’t have a good answer for our critique so they change the question to answer something they can defend.
First, the basics: Most Democrats are going to vote for the Democratic candidate, most Republicans are going to vote for the Republican candidate, and the independents are usually going to split somewhat evenly. So the proportion of the three groups more or less determines which candidate the polls are going to show ahead. No one claims to be able to predict, with absolute certainty, what the partisan makeup is going to be on Election Day. But we do have a range from recent history — from even in 2004 and a seven percentage point advantage for Democrats in 2008.
Now Geraghty lays out the biggest gap in defenders of current sampling
If a pollster believes that the electorate will be even more heavily Democratic in 2012 than it was in 2008, I’m willing to hear those arguments, but I think it’s a tough case to make.
Now the argument for why turnout will not meet or exceed 2008. Something I have argued many times:
The last presidential cycle was a perfect storm for Democrats — an unpopular GOP incumbent, frustration over wars overseas, a terrifying economic meltdown, a Republican nominee who had spent much of his recent career fighting his own party and who openly admitted he wasn’t focused on economics, the first African-American major party nominee in U.S. history… This year you have Obama running as an incumbent in an extremely tough economy, a more aggressive GOP nominee, the grassroots energy of the Tea Parties, a huge change in each party’s financial resources, the novelty of making history wearing off, and now our embassies under siege in the Middle East… And then there is the shift in the number of voters who are registered voters in each party…
Defenders of the polling mischaracterizing our complaints about sample sizes (I think I got so fired up I commented in Cilizza’s comment section here)
Yet our objection keeps getting misstated and twisted by poll defenders time and again. Here’s Chris Cillizza, claiming the complaints are “a series of false assumptions none bigger than that because the country has been virtually evenly divided on partisan lines for the past decade or so that the party identification question should result in something close to a 50-50 split between Democrats and Republicans.” No. I do not demand an even split, nor do any of the other folks paying attention to this factor. I do think that a split of D+7 or more is excessive, and that a D+3 or D+4 divide — halfway between the GOP peaks of 2004 and 2010, and the Democrat peak of 2008 — is more likely.
Because for much of this year, in quite a few national polls, we’ve seen Romney winning almost all the Republicans and hold a lead among independents, and still trail Obama, because Obama is winning almost all the Democrats, and Democrats make up such a large share of the sample. Possible? Sure, anything’s possible. But if a pollster is going to offer a hypothetical electorate that looks different from everything we’ve seen before, I’d like to know why they think this is the case…What we see in the most disproportionate poll samples is confirmation bias. To many people covering this race, Romney should be trailing badly, Republicans are flailing desperately, and Obama is running an exponentially better campaign. Thus, it makes perfect sense for the electorate to be even more heavily Democrat than it was in 2008.