Thus the ultimate question is not whether a former president can be investigated but whether one should be. What is best for our country? How can the country uphold the rule of law and the idea that no one is above the law, without driving itself into civil discord and risking fatal polarization?
There are no easy answers here. The best one can offer is a discretionary judgment that has some convincing rationale and offers a plausible way forward. In my view, the outlines of this are clear: It would be too great an affront to law for a president to have perpetual immunity. At the same time, the risks of polarization from criminalizing decisions that were made by the president during the course of a presidency is substantial. Alternatives, such as impeachment and loss of an election, exist that can address those wrongs.
Hence, let us try to thread the needle: Forgo the prospect of prosecution for actions undertaken while in office, but recognize that crimes a president commits while a regular citizen should not be excused just because he or she has served as the president of the United States.
This is not, by any means, a perfect solution. In our parade of horribles, there might be edge cases of conduct that occurred while the president was in office that would be so egregious we would want them to be criminally addressed. If, say, a hypothetical future president committed murder while in office, we would hope that a post-term prosecution for that offense would be permissible.