That depends who you ask .. "they" are a very small part of US politics ... their beliefs are not shared by a majority .. in fact they are not even shared by a small minority .. given that their views are not "mainstream" and are supported by a very small sample of the US population .. I would say that you can comfortably call their agenda "Extreme" ...
Not really - would you be in favor of the balanced budget amendment if the party was also in favor of raising taxes on "the rich" ? This is not about stopping the government spending .. when it is coupled with their unwavering belief that nobody should ever pay higher taxes ... it in fact turns out to be a way of strangling social welfare funding under the guise of reducing the debt ..
Its a simple bait and switch and anyone with half a brain can see right through the brown colored stuff that they are shouting out to anyone that will give them 30 seconds or more of airtime.