If you weren't already hip to this, polls can be very funny things. There are some pollsters that manage to produce polls showing just about whatever the person commissioning the polls wants them to show. There are polls, sometimes widely reported polls, where the sampling is seriously askew--say, for example, where 2/3 of the respondents are Democrats or something. There are polls that poll "voters," and then there are polls that show "likely voters," that is, people who actually voted in the last couple of elections.
Some polls have better track records than others. My understanding is that Rasmussen has been the closest during the last couple of election cycles.
But you know, when I'm curious about the polls, I generally head straight to RealClearPolitics. They show polling results on a wide variety of subjects, and they show results from several pollsters, and they average those polls, too. It's worth checking out when you have questions. Like, this morning on Drudge, I followed a link where the writer claimed that polling now shows that Democrats are ahead in generic balloting. Turns out some of them do, but most of them don't. Same writer also claimed that President Obama's job approval numbers are heading up. And true, the average does show that. But then, you look at the polls involved in the average, and the ones showing the president with higher approval ratings are CNN, the Washington Post, Bloomberg, CBS News, and Gallup. Rasmussen--remember what I said about Rasmussen?--shows him down, as does USA Today/Gallup, and some others. Nor are the differences between the polls slight. I suspect that there is something going on in the sampling. You can make up your own mind.
At any rate, I find this a useful tool. You might find it so, too.