From a site that is not biased propaganda:
http://www.theatlantic.com/politics/archive/2012/09/are-polls-skewed-too-heavily-against-republicans/262834/
"
Gripes about the party-ID composition of poll samples are certainly not new: Eight years ago,
Democrats were claiming polls showing a surge in Republican identification did not accurately reflect the makeup of the electorate.
Now, it's Republicans making the case their voters are undersampled.
Schwartz, whose institute conducts polls in battleground states for CBS News and The New York Times,
asserts that pollsters who weight according to party identification
could miss the sorts of important shifts in the electorate that could be
determinative.
"A good example for why pollsters shouldn't weight by party ID is if
you look at the 2008 presidential election and compared it to the 2004
presidential election, there was a 7-point change in the party ID gap,"
Schwartz said. Democrats and Republicans represented equal portions of
the 2004 electorate, according to exit polls. But, in 2008, the
percentage of the electorate identifying as Democrats increased by 2
percentage points, to 39 percent, while Republicans dropped 5 points, to
32 percent.
Asked specifically about GOP complaints regarding the party-ID
composition of public surveys, Schwartz said: "They're the ones trailing
in our swing-state polls."
"There are more people who want to identify with the Democratic Party right now than the Republican Party," he added.
"
Hewitt is altering the polls based not on the science of sampling, but on his own personal views.
Don't like the polls? Accept that your campaign is not doing a good job? Nahhhh, say they're wrong.
In less than 50days we will have the real answer.