In alternate reality land there's a new CT making the rounds, which goes something like this:
The reason Obama is leading Romney in an overwhelming number of State polls is that the pollsters are not asking enough Republicans for their opinions. The pollsters are in the tank for Obama. It's supposed to be a 50-50 country -- so pollsters should sample it that way.
Then they go on to cite "anomalous facts" like these to back up their Pollsters "Conspiracy Theory" to intentionally skew the country away from a "fair" the 50-50 split:
Amazing Coincidence: Obama Surges in Poll That Oversamples Democrats Even More Than Previous Polls Oversampled Democrats
by Jeff Brokaw, jbrokaw.wordpress.com -- Sep 16, 2012
Shocking, eh? Media polls nearly always oversample Democrats, but suddenly, right before the start of the primary season, right when it would be politically convenient for Democrats, they increase the oversampling to be much larger than the stated margin of error for the latest poll.
[...]
Here is the data regarding the political affiliation of those individuals who participated in the most recent Washington Post/ABC News poll:
Democrat 32%
Republican 25%
[...]
And here then is the political affiliation of those individuals who participated in the Washington Post/ABC News poll from November:
Democrat 29%
Republican 26%
[...]
Note the difference between a conspiracy, which implies a few crazy people meeting in the park to plot against the world, and monolithic behavior driven by a world view: same outcome, two different scenarios. Just because journalists and polling organizations all behave in some consistent way politically doesn’t prove they are conspiring, but it does prove they are using their power for political propaganda. Because they all want the same thing: centralized government wealth and power.
[...]
Funny thing is,
AFTER the person has been randomly selected for participation in a survey,
THEN they are asked about their Party-affiliation, usually towards the end of the call.
It's not the other way around -- scientifically-based Pollsters don't target Party-affiliation first -- that would be skewing the sample. And without randomly selecting your input data, the predictive ability of polling will fail. No honest pollster wants that.
If you want to know the "average IQ" of students in your school, or State -- but only "tested" (polled) the A-students -- well what kind of "average" would you get?
One with a very high-opinion of yourselves ...
There is another explanation, one a bit more reality based.
Simply put: The Republican Brand stinks -- and people are fleeing from it in droves.
No, The Polls Aren't Oversampling Democrats
by Nate Cohn, The New Republic -- Sep 27, 2012
[...] Put it this way: the Republican Party is not popular, the Republican Congress is not popular, and the Republican nominee is not popular; so how could anyone be especially surprised if a couple points worth of Republican leaners have now decided to characterize themselves as “independents.”
[...]
An influx of Republicans into the “independent” column would also explain why Romney remains close among independents despite trailing nationally. It’s also easy to envision how a few independents who lean-Democrat might have switched to the Democratic column following the DNC, which would prevent Obama from gaining among the remaining independent voters who would lean slightly more toward the GOP. If true, Romney's strength with independent voters and the Democratic advantage in party-ID might not be contradictory, but inextricably and coherently linked.
[...]
These trends are consistent with the best available data on party-ID. A yearly Pew Research survey tabulating tens of thousands of voters shows that while Republicans haven't gained new adherents over the last four years, Democrats have suffered losses, the number of independent voters have increased, and those independent voters increasingly lean toward Republicans.
Party-Identification is not a static thing. It's not set in concrete. There is no law that "enforces" their hypothetical 50-50 split -- except their own wishful thinking.
If you want to know the "average IQ" of students in your school, or state -- but only "tested" (polled) the A-students -- well what kind of "average" would you get?
Probably just the answer you want. But not one that is an accurate measure of the overall population.
However if the sample population pool of students had "overall" been becoming "smarter" so that there generally were more A and B students population-wide, well that increase in IQ should show up in your polling averages, when randomly selected. That's kind of the point of "averaging" -- to find a common measure which characterizes the entire population being measured.
Republican CT advocates would have us only sample the D and F students -- or at least to "oversample them" to make up for the fact that D and F students, are getting harder and harder to find. Since being dumb isn't cool anymore, so we need to double count them, to make up for their fading impact.
The same thing could be said about the Republican Brand -- given the choice to self-identify between D and R -- What randomly selected Independent person given current reality-based events, is going to keep saying that they are "leaning R"?
Fewer and fewer all the time -- and the pollsters are noticing these overall population-shifting trends. Populations are not static things made of concrete. People remember. People change.
Sorry R's -- a majority of people just aren't buying your act anymore. Most American people want results. ... More and more all the time.
Reality. It's not that hard of a concept to grasp Republicans -- you should try it sometime.