If Donald Trump does run for re(ish)-election in 2024, some of the obstacles will be the same as in 2020, some will be different, some will depend upon the ever-shifting vagaries of the political landscape, and some will depend wholly upon Trump doing what he does best while avoiding what he does worst.
To start with, there will be the legal issues. Despite the utter absurdity of the challenge, Marc "I can't believe I'm not at least wearing an ankle bracelet" Elias and his horde of Democratic lawyers will challenge Trump's ability to serve based upon his participation in an "insurrection." (One of the reasons that term will be used, literally and figuratively, ad nauseam in the January 6 committee report will be to lend a wafer-thin layer of credence to the claim). Those challenges will take place at every level of the judicial system: local, state, and federal (the warm-ups are already happening), at the very least to inflict political damage, if not actually create a legal bar to his running and, unlike the lackadaisical response to the wholesale voting law changes enacted in 2020, must be met head-on.
This legal effort will work hand-in-glove with Deep State usual suspects leaking like a racehorse made out of a sieve everything they can think of to upend his candidacy.