Several years ago I heard someone say, "Democrats are a run away train heading to socialism. Republicans are the breakmen just slowing the ride."
I prefer Milton Friedman's analysis. Instead of getting all emotional over government spending, simply think of your income being spent by yourself or by government. What percentage are you willing to have spent by government.
It's a practical question. Obviously, national defense and police are authorized by the constitution. After that it's a matter of politics.
I personally would like to see a constitutional ammendment that limits government spending to a fixed percentage of GDP.