What's up with opinion polls?

Opinion polls have long been apart of American politics. These polls no longer just reflect public opinion; they also shape it, some experts said. But when the polls get the results wrong, many wonder if we can really trust them.

Election Day is now just 13 days away and most of the recently released poll numbers show Obama having a double-digit lead in the presidential race. But how accurate is the pollster's electoral math?

There are hundreds of polls being conducted by different people and organizations. So how do they work?

Instead of surveying all 300 million Americans, experts said a smaller group could reflect the opinion of the entire nation. To make sure it's accurate, pollsters have to sample an even amount of various demographics like gender and political affiliation. For national polls, most sample about 1,500 people.

The majority of these opinion polls are conducted by phone, UT Tyler political science professor, Dr. Larry Carter, said. "Most of the polling is still based on random numbers, which are generated by computer," he said. "But now most people don't answer the phone, I don't answer my land line." This is what sometimes makes the polls inaccurate because younger voters don't have landlines.

Another problem, experts said that 50 percent of people aren't going to say whom they would vote for, making the sample pool even smaller. "People also sometimes just won't tell the truth when there asked whom they voted for or whom they're going to vote for," he said.

Dr. Carter said to take these numbers with a grain of salt. "Polls are kind of a form of entertainment anyway. It might help the candidates see where they need to spend money, but for all of us, the best thing to do is wait till after the election to see who won."

Obama's current ten-point lead on Senator McCain is the largest lead so far, according to a poll from the Wall Street Journal/NBC News.