I'd like to make clear that I believe presidents should be immune to prosecution for making bad decisions. Something that seems like a good idea at the time may turn out to be horribly wrong, with disastrous consequences. But presidents don't have crystal balls or time machines. They don't know how things are going to turn out. For example, Trump mishandled the Covid pandemic in its early stages. He called media coverage of the outbreak a hoax (yeah, everything's a hoax with him), he downplayed its seriousness, dithered about the best way to handle it and undermined his top people at every turn. Even though I believe that everything that he did was based on inflating his own ego (which is not a crime) it's theoretically possible that he really thought that playing down the lethality and communicability was key to minimizing panic. At least it would be difficult to prove otherwise. An example from the other party: President Biden's withdrawal from Afghanistan was without a doubt chaotic, the melting away of the Afghan military gave the Taliban a free supply of military supplies and thirteen soldiers were killed by a terrorist attack during the withdrawal. But was it criminal? No. Could it have been handled better? Probably. But it was well within a president's authority to do, and shouldn't be subject to second-guessing by prosecutors.
Presidents while in office are exempt from regulations that apply to federal employees, for example, conflict of interest laws do not apply to the president. Justice Department guidelines prohibit prosecutions of presidents while in office. The Mueller Report made very clear that Trump's actions constituted obstruction of justice, but the fact that he was the president precluded any action. The only consequence a president can be subject to is impeachment and subsequent removal from office. As we saw from Trump's two impeachments, removal requires such a high bar that it's virtually never going to happen. But what about illegal actions taken before or after a president's term of office? What about actions taken while in office but that clearly are not part of a president's duties? (Like inciting an attack on Congress) Should a former president still be immune?
Other than in the unlikely situation where there isn't deep divisions among the electorate, any prosecution of a former president, or presidential candidate, is going to cause an uproar. In the current political climate it's already causing an uproar. The question should be whether allowing a president or former president to break the law with impunity is good for the country.
Losin' Don and his cultish supporters reveled in chanting "Lock Her Up", somehow think Dr. Fauci should be arrested and are fixated on Hunter Biden's laptop. Trump himself mused about whether Secretary Clinton "should be allowed" to run for president while being investigated by the FBI, yet here we are with the front runner of the Republican party under indictment, with several other investigations underway that may result in additional indictments. And the really scary thing is that nothing prevents him from running, even if convicted and jailed. We are entering a scenario where an incarcerated felon may need to petition to be released in order to sworn in as president.
Whatever happens next, it will be messy.