Would in a sentence.

...more context...

They were about pardons-desperate pleas from thieves and embezzlers and liars, some still in jail and some who'd never served time but who nonetheless wanted their good names cleared and their beloved rights restored. All claimed to be friends, or friends of friends, or die-hard supporters, though only a few had ever gotten the chance to proclaim their support before that eleventh hour. How sad that after four tumultuous years of leading the free world it would all fizzle into one miserable pile of requests from a bunch of crooks. Which thieves should be allowed to steal again? That was the momentous question facing the President as the hours crept by.

I wonder...

What does would mean or function as in the above sentence?  (Only the past tense of will? Or subjunctive mood? Or to indicate uncertainty?)

Thanks in advance!

 I agree that's an expectation made using a subjunctive mood construction, but made in the past, at the time the President considered the situation, looking towards the future as seen at that time.

Think about reported speech, in which

Will->would (both with the meaning of expectation

He thinks (now) how sad it is that after four tumultuous years of leading the free world it
will all fizzle into one miserable pile of requests from a bunch of
crooks.

He thought (then) how sad it was that after four tumultuous years of leading the free world it
would all fizzle into one miserable pile of requests from a bunch of
crooks.

will ~ is going to

would ~ was going to

Remember, the author has the advantage of knowing what finally happened after that point in the past -- even though the actors in the narrative did not know their own future at the time.

How sad that it was all going to fizzle into ...

 (I don't see anything subjunctive here, by the way.)

CJ