The current generations of the politically active general public seems to distrust and hate scientists and engineers, and they'd rather all that wonderful "free" government money be spent on turkeys in every pot and cars in every garage or some pet social program instead of sending big tin cans to outer space to prance around and look for little green men. It's a shame to see the US fail to invest in its own technological success, but I have some faith that the readers of this site don't always share that particularly mundane outlook.
You paint with too broad a brush. But the balance is far too even to pass even modest R&D budgets, especially in the pure science fields. Show them either a direct and imminent threat or a pot of gold to be made and the budget will suddenly appear.
Lead me not into temptation... I can find it myself.