A new Washington Post/ABC News poll has Barack Obama leading Mit Romney 49-46 among registered voters. The 3 point lead is within the margin of error, which is plus or minus 3.5.
Properly analyzed, the poll presents better news for Romney than meets the eye. That’s because, as Ed Morrissey points out, Republicans are woefully under-sampled by the Post. The sample includes 32 percent Democrats, 38 percent independents, and only 22 percent Republicans. But Republicans were 35 percent of the voters in the last election and 32 percent in 2008. Heck, the Post could probably find a sample with close to 22 percent Republicans if it polled passers-by outside its headquarters in Washington, D.C.
Looking at the Post’s sample from another angle, it contains 10 percentage points more Democrats than Republicans. In 2010, exit polls showed that as many Republicans as Democrats voted. And even in 2008, a bad year for Republicans, the difference was Dems +7 points.
The under-sampling of Republicans is particularly significant because the Post finds “across-the-board partisanship” among respondents. “People’s views,” says the Post, “are stubbornly related to their underlying party leanings.” Therefore, Obama’s “lead” in the Post’s poll might vanish in a sample that contained the 2008 mix, and Romney would likely lead if the 2010 mix were used.