Polls are inherently flawed. 

You might have seen the pollster at the mall flagging down people to conduct a 'quick survey'.   Ever notice how many people just walk on by?  This in itself makes the poll a flawed sampling.  Those who choose not to be bothered, ignore the entreaties of the pollster.

Those who choose not to be confronted, not to be disturbed, those who have somewhere to go and are likely deep in thought, take a pass on the pollster.

Did I just describe a Conservative?

Do Conservatives who are home for the evening reach for the phone when the caller ID says "Washington DC" or "Political Call"?  I don't.

There is a dangerous game being played by the politicians and the pollsters.  Whenever there is a great deal of power and money at stake, one can assume there is power and money in play.  What does this do to the integrity of the polling services?  Are election polling services far from the Television ratings game?

Politicians know that there is a certain segment of the voting public who want to pick a winner.  Those voters want to select the victor as if it is a contest.  They can bask in the glow that they somehow made the proper choice and share that glory with their friends and at cocktail parties.  Polling results play to these people. Sadly, the percentage they comprise can determine an election.  Remember how "chic" and "hip" it was to be an Obama backer in '08?

As to the accuracy of pollings and exit polls. The 2010 mid term elections were supposed to be close.  It was a landslide for the GOP.  The Scott Walker recall exit polls indicated the outcome was too close to call.  He was preserved by a 7% win.

Polls only measure the thoughts of  those who choose to submit to the polling.  I suggest Conservatives often choose not to be involved or share their thoughts in the framework that is election polling. This is consistent with Conservative nature.  Leave me alone. Laissez Faire  in a sense. Realizing the skewing, the results that often fail to mention how the question was actually phrased, and the money and power involved in the process, one can see why those of the Conservative mindset would shun the pollsters.