Exactly.
I view them as a kiss of death
You are dead-on accurate with this statement. Here in the beach cities district, I've seen such people first hand. They are invariably politically obtuse; clueless as to how government, campaigns, and politics work; yet adamantly certain only their point of view is valid.
They have zero ability to step outside themselves to examine how and why it is that others have different points of view. Not necessarily to agree mind you, but even to examine another's way of thinking.
They also are incapable of getting the point that there can be valid gradations in political positions, some of which are not very far removed from their own positions. If a position is not presented in exactly the manner they are capable of responding to, then it is rejected out of hand. Anyone who is essentially not a political clone of themselves is not just different, or possibly mistaken, noooo...they are BAD. They are the enemy.
People given to such rigid thinking scare the bejeebers out of most ordinary folk who pay scant attention to politics. Time and time again in this moderate district currently represented by Jane Harman, I've seen such people refuse to support solid Republican candidates. They continually tilt at windmills by chasing the least electable hard-right candidate in the primary. Then they whine and pout when their candidate inevitably loses, so they either don't vote, or they vote Libertarian to "send a message" that is never received because politics doesn't work that way.
I am deeply dismayed to see this phenomenon spread across the country.