I use www.realclearpolitics.com to get an accurate picture of what the American people think. During the last election--if you took the AGGREGATION of ALL the polls listed on that site--you got the EXACT percentage margin by which President Bush won!!
So when people cite any particular one poll, I always take that with a grain of salt. However, if the average of ALL polls agree with that poll--then you cannot ignore it. Hence, the incredibly low approval rating of the President are not to be dismissed--as all polls taken together DO show that he (and the entire Republican Party in the next election) have a major problem.