But where in the Constitution does it say that he has immunity?

Right next to the language protecting a woman's right to choose. Do you really want to go down the "where does it say...?" road?

This case must be argued at the policy level. The same Trump whose crimes you want to punish has threatened, if he is elected, to prosecute Biden. Doesn't this case cripple that Trump by putting Biden "above the law"? Doesn't it make Biden king right now? Public policy is party neutral. The case cannot be properly analyzed without putting the shoe on the other foot.

This case has arisen because the Senate did not do its job. If Trump had been convicted in his second impeachment, he could not have held the office and would have had no reason to "stop the steal." Mitch McConnell (may he eat shit and die) could have saved the country.. But we elected enough asshole senators to acquit Trump. That's on us. We are getting the government we deserve.

If the President is a criminal, we are fucked. All the rest is commentary.