The polls -- commissioned, after all, by media outlets -- are designed to extract the most advertising dollars from both campaigns. Presidential elections are the political Super Bowl for the MSM, and political advertising differs from the run-of-the-mill since it has to be paid for in advance. It's cold, hard cash for a media sorely in need of it.
So you bet they'll make it look close until the bitter end, on occasion showing one candidate or the other building a lead so the other candidate increases his advertising buys.
These polls are all about money for the Drive-Bys.
I'd add that as the election grows closer, and the MSM and their hired pollsters decide they've wrung every last dollar out of this thing, the polls will begin to more clearly reflect reality, in order to maintain the polling firms' reputations.
That's also been my observation in the past. The MSM use the polls to manipulate opinion/elections (to charge up 'their team', and to demoralize the opposition). In the day or two before the election they rush closer to reality -- as those are the numbers that get published to establish their credibility (their final poll numbers vs. the actual election outcome). Until then, its all propaganda - and these poll numbers are to be used only for amusement purposes...
Absolutely. The only poll which should be given ANY, although small, amount of cred should be the one the week before the election. Even then, not much.