You mention FOX polls, so here you go.
"The
Fox News poll released today continues the trend of skewed polls that over-sample Democratic voters to produce results favorable to the president. The poll reports
President Obama leading over
Mitt Romney by a margin of 48 percent to 43 percent. But this is based on a sample that includes eight percent more Democrats than it does Republicans for an electorate that is made up of two percent more Republicans than Democrats."
NBC
"A recent
NBC News/Wall Street Journal poll release last week showed an Obama lead of 50 percent to 45 percent using a sample that under-sampled Republicans by 12.6 percent and over-sampled independents by 8.8 percent.
Unskewed, this poll's data indicated Romney leading 51 percent to 44 percent. The fourth picture in the slide show illustrates the skewed sample used in this poll."
CNN
"The infamous
CNN/ORC poll showed Obama leading by six percent, 52 percent to 46 percent, almost the margin by which he won in 2008. But the survey sample was doubly-skewed, over-sampling Democrats 17.1 percent and under-sampling independents 25.0 percent.
Unskewed, the data from this poll would reveal a 53 percent to 45 percent Romney lead. The last picture in the slide show illustrates the skewed sample used in this poll."
