Different viewpoints in polls depending upon who they poll.  You can do five polls in the same state and they can all vary as the people they call are randomly chosen.  If you are going to conduct a poll with a specified number of one thousand people randomly chosen and the majority of those people are of one party or the other, whichever party is the majority in that poll will determine the direction/results of that particular poll.

So say if a poll made contact with thirty percent of people who said they are republicans and sixty percent who said they are democrats the results calculated for republicans will be based on thirty percent out of one thousand people registered as republicans...hardly what one could establish as an overall view of all republicans in a particular state.  That's saying three hundred republicans spoke for every republican in a state.