[p_l]

Apollo program got to the point that NASA budget was >4% of total federal budget.

And Apollo program itself was, IIRC, over half of it.

Never since NASA had such funding and political will to just let them try to get a stated goal. History of projects since Apollo is full of every attempt at making things simpler and more reusable either getting canceled, blown with congressional requirements for pork-barrel (SLS), damaged by needing to beg for money from organizations with different goals (Shuttle is a great example), smothered by budget cuts resulting in reuse plans getting canceled skyrocketing per-mission cost (Shuttle, Cassini), and that with NASA being effectively prevented from doing iterative approach and ending having to gold-plate everything to reduce risks on the often "once in a lifetime" launch.

[Symmetry]

It's important to remember that Apollo was one of Kennedy's signature political projects at the time he was assassinated, which was an important factor in its political viability.

[p_l]

It had considerable impact on why it had so much leeway compared to pretty much any later work by NASA.

When Apollo ended, "space race" ended for USA and it decided to stop on laurels.

[coldtea]

>Apollo program got to the point that NASA budget was >4% of total federal budget

Given the figures in TFA, that points to a much smaller federal budget and much smaller government expenditures in general, than to less absolute (inflation adjusted) money for this over Apollo.