The Constitution says that in cases of impeachment, "the party convicted shall nevertheless be liable and subject to indictment, trial, judgment and punishment, according to law." It does not except the president. But what impeachable offenses aren't covered by the new doctrine of immunity?
i think akhil amar reed captures something very important, which is that the roberts court rewrote article ii, which explicitly states that a president can be held criminally liable after impeachment (and which has long been understood to mean that he can be held liable after leaving office)