I wrote my dissertation and my second book on the rule of law, and think it's the most fundamental part of any democracy. So I read @jonathanchait 's piece on prosecuting Trump with real interest and concern: https://nymag.com/intelligencer/article/donald-trump-criminal-prosecution.html
My first article was about how competing definitions of the rule of law: https://carnegieendowment.org/2005/01/21/competing-definitions-of-rule-of-law-implications-for-practitioners-pub-16405. I've since boiled it down to just a line: The rule of law exists when the powerful are accountable to the same laws as others, and the state upholds law among the populace.
The catch-22 in a polarized society, is that holding the powerful to account - regardless of whether they are guilty - delegitimizes the rule of law and the state itself, unless it is conducted in a way that is seen as above politics. That requires cross-partisan involvement.
Yet we are not only polarized along a left-right axis, but also an elite-non-elite axis. Even if respected elites of the left & right came together to prosecute, many within the U.S. would see an elite conspiracy against "the people". Populism doesn't go away w/an election.
That leaves a deep problem with how to prosecute a head of state who may have broken laws. The need to uphold accountability would likely further delegitimize the rule of law itself. It's a real risk, given how polarized U.S. views of courts and police are & skepticism of elites.
Instead of making this up, we can look to other countries that have dealt w/this problem. Countries like Brazil prosecuted corruption in such a partisan, lopsided manner, that it probably helped entrench the idea that all sides were corrupt and that prosecutions were political.
Major lustrations of all members of a corrupt administration remove institutional memory and create significant anger that can lead to blowback and the return of a revanchist party - see Serbia.
The European Commission for Democracy through Law offered guidance for how Ukraine could purge corrupt officials while retaining law. Among other recommendations, they suggest elected officials be exempt from this form of lustration, as voters have the right to elect.
South Africa is also dealing with this now, as Prez Ramaphosa tries to deal with the incredible level of state capture under former Prez Zuma. His bipartisan commission of inquiry brings out facts, but can't compel prosecution.
That may be the best model for the U.S.. A high-level bipartisan panel that uncovers facts. And then, when elections offer the option, a pardon from a Dem president.That is not justice. But it allows facts to be uncovered while elites acknowledge their role in our broken society.
Meanwhile, prosecutions and removal for all below Trump who broke the law, to strongly warn future appointees. And new laws to create bright lines on Presidents who now operate with far more impunity than they should. That requires a Congress that would pass them, of course.
Ideally, the offer to pardon Trump, or to hold a commission rather than a prosecution, would be a deal for strong new laws to control future behavior. The U.S. has long relied on norms not laws. Those norms are breaking under our polarization, and we need bright-line laws.
Is this the ideal of the rule of law? No. And after time has passed, as with Spain post-Franco in Daniel Ziblatt's discussion, the state needs to reopen these wounds and deal with its past. But in the immediate aftermath, a highly polarized state needs to move out of polarization