The President (mostly his team) submits the budget proposal for the upcoming FY (starting in the 3rd quarter) to Congress. The House reviews it and tinkers with it, then passes it over to the Senate, which does the same. Then they go to reconciliation and ultimately both houses of Congress pass the HJR. The president cannot veto a JR, so the line item veto would accomplish nothing.
Passing the budget through Congress amounts to allocation of funds. Once that is done, the President (mostly the executive departments and agencies) are at liberty to disperse the allocated funds. They are not required to do so, as far as I can tell.
If line 6129 is $1million for research into kittens’ reactions to Rule 34 Kittehs, the department that would handle that (Education?) may decide that only $100,000 is needed to support that project, but I do not believe that they are permitted to divert the remaining $900,000 to some other pet project (without some clever chicanery).
In other words,
[ul]
[li]the President tells congress, “I need this much”[/li][li]Congress tells the President, “you can have this much”[/li][li]the President hands what he is given, limited by the bracketing of the HJR[/li][/ul]
He can selectively hand out less, if it seems appropriate and will not piss off important members of Congress too badly.
I, for one, am not a Veteran. I do, however, believe that the words “Veteran” and “Ted Nugent” do not belong anywhere near each other. “Ted Nugent” and “shit yer pants” are a nice fit.