You have to remember that it is only a minority of voters are voting in the Republican primaries. If a state has closed primaries and the state is split 50/50 between Dems and Reps then only 50% of state can vote, and primaries have very poor turnout. We are probably talking about 15% of voters actually turn out for primaries. This is why they try to appeal to the nutters, because those people do tend to vote at a higher rate.
This is but one reason, in a myriad of them, why I pay no attention to polls. Like you said, only a handful of people are voting in the primaries, and they usually are diehard politickers.
Secondly, polling is often manipulative. Pollsters are often asking questions in a specific way to get the answer they desire.
Thirdly, it's unreliable at best. One polling agency report virtually the exact opposite of another.
More to the point, it creates a false sense of security and fosters self-fulfilling prophecies. The media has a tremendous amount of fault in this, reporting these polls, thus giving the viewer a skewed idea of who is "in the lead." Because of this, people are more apt to vote for whoever will get the other guy out of office rather than simply voting for who you think is the best candidate.
And most importantly, what fucking difference does it make what other people are voting for? Who gives a crap. All that should ever matter are the reasons YOU want a candidate to win.
I pay no attention to these polls and strongly encourage others to do the same.
"Reason obeys itself; and ignorance submits to whatever is dictated to it" -- Thomas Paine