It sure would be nice if with the wave of a pen all unconstitutional spending were ended. In both reality and in theory such is possible. All it would take is people in Congress and the White House to be committed to actually upholding our Constitution.
In reality it is also impractical because finding people with this sort of will and the courage required to actually do such is nearly impossible. Cowards abound in Washington and unconstitutional spending has become so ingrained into American society and so many Americans have their hands in the cookie jar, so to speak, that abrupt abolition of such programs is most likely impossible short of a complete uprising of the American people against such programs. I hold out faith hope that such might occur but I will not hold my breathe.
A gradual abolition of such programs would certainly be acceptable and preferable to the current continuation of them although the outright ending of them would be most preferable.