it is spent by Budget - 100% (other than when POTUS games (D or R) are tried
my point - money earned here like all $ but Social and Medicare and highway tax (and tiny odds and ends) ------ goes to one pot
they are not diverted for pet projects invented by POTUS (ACA or WALL)
and once in pot - given we have a deficit - the money from F and F - now undistinguishable for other income or revenue flow out to departments per budget