He could argue it, but he'd be clearly wrong.

Fair enough. But until he is adjudicated wrong, he continues as if he were right.

First, he'd have to be charged with a crime, something the DoJ won't do while the president is in office. Only once he's out would they even start investigating. Once charged, he could argue it in court. File endless motions before trial. File every interlocutory appeal that is even remotely possible. Appeal every loss there to the USSC. Then finally go to trial, file more motions during trial before losing. Then file an appeal, file endless motions there before losing. Lastly, appeal to the USSC and lose there. Only then will he actually be wrong. Until then, he is presumed right - or innocent.

Of course, by then we're all dead of old age.

As I think about it more, that's the real problem here.

If I remember correctly, there was another Trump case (or maybe just another appeal in this case) that the USSC did not grant cert, presumably to let the lower courts do their job, find the facts, and then allow them to make a ruling. This time, they granted cert and threw an entirely new process into the mix, forcing the district court to back up quite a bit and do more work before going to trial. They could have denied cert, let the lower courts do their fact finding job and then take up the case with a much fuller record on which to base their decision. Heck, it's even possible they wouldn't have gotten the case back at all if the district court found Trump not guilty.

While they did move a bit quicker than their usual snail's pace (moving up to a tortoise pace, perhaps?) it's still a slow process when some degree of speed is needed. Had they denied cert, the worst scenario for their workload is that they get the case back, make this same decision, and have to remand back to the district court to do a bit of additional fact finding on this middle circle of presumptive immunity. They'd still only touch the case once, instead of the two times they will have to deal with now.

Most importantly, the people of the country would have some important facts available to them on which to base their voting decisions in November. Now the people will not have those facts. For a country based on an informed electorate, keeping them uninformed is a very bad look.

--Peter