I think america was great just after WW II, then industrialised commercialism gave only the illusion of greatness; the space race brought back greatness temporarily, but wars took the shine off. Now, big, but not great. Still better than communist countries though.
Draining the swamp is a stupid analogy.
Swamps are where the little fish spawn, which turn into the big fish that you want.
Swamps are full of diversity and activity and life.
A drained swamp stinks as it decays and dries out, everything dies, then the unprotected organic goodness blows away, often leaving acid sulfate boggy soil.
Not a good foundation for anything except developing another vibrant swamp.
Translate that to political / community dynamics.
Trump = chump.
Come Sir, we know the variety of swamp, for example the type where dissolved oxygen is low, mosquitoes breed and little fish hardly grow beyond the size of small frogs... And then as you say, if the swamp gets smaller, there may be that 'acid sulfate boggy soil' that stinks partly because of rotting carcasses from the past.
But the Swamp Mr. Trump meant is more dynamic; includes political alligators ...
--XX
I'm not particularly a fan of Trump - he is an ego maniac narcist and because he calls illegals rapists and has blonde hair, etc., he is racist.
But here's an example on racism. George Floyd would've been another statistics local to US but because Trump was President it boiled all over the world media / & flamed up world against our own internal police brutalities. Even Hong Kong was watching.
---xxx
On the World Stage:
Now with world economy projected to go downhill the question the world faces is in which direction do they lean:
Make in America, make America great ... or
Allow China to take over world economy, gain world dominance
It depends on who America elects: Trump ... or Bidden from the Swamp.