Does the U.S. Supreme Court have jurisdiction over the constitutionality of an impeachment?

Question

A question arose on Politics SE asking why the constitutionality to continue an impeachment trial (whose prime purpose is, presumably, to remove an official from office) after the official has left office has not been decided.

There was a disagreement in the comments: While it is almost universally agreed that there is no judicial review of how the trial was conducted, including its result (because it's the Senate's supreme privilege), the case was not so clear with a review of whether the impeachment was constitutional to begin with.

Could the Supreme Court declare an entire impeachment process unconstitutional?

Answer 1

Part of the problem you'll find is that there are so few impeachments in U.S. History (Only 21 articles of Impeachment have ever been drafted, of which only 8 resulted in convictions) and SCOTUS is so selective on cases it chooses to hear, that only one case has ever been heard and that was upheld (Nixon v. United States). In that case, SCOTUS ruled that it did not have jurisdiction to rule on the legal question before it (was the new trial format a proper trial by the senate), but did not have an opinion one way or another to suggest that SCOTUS could not review other cases that come before it. One of the reasons they also haven't is in order to have a legal case in the U.S., the plaintiff must suffer actual harm. More impeachments ended without a conviction than with either acquittal (8), resignation before trial conclusion (4), and expulsion from senate (1, and will never occur again as Congressional office holders are not impeachable following this particular case).

Since no harm was caused and courts do not rule on hypotheticals, a case with actual harm (conviction) must occur in order for SCOTUS to even consider hearing the case. Nixon does not bar SCOTUS from hearing more appeals resulting from Impeachment, it only bars those relating to the manner in which the senate chooses to hold the trial.

Answer 2

The answer by @hszmv is correct and I fully agree with it. I would add a few additional points:

Not All People Impeached Are Removed From Office

A ban on holding future public office is imposed in only a minority of impeachments, and can only be litigated if the person seeks to hold such an office and has a non-speculative chance of obtaining one. In some ways this is the provision most ripe for litigation in the courts because it lasts the longest.

SCOTUS doesn't have a monopoly on constitutional law

Every single federal judge has the authority and the obligation to rule on constitutional issues that come before that judge. The U.S. Supreme Court does not have exclusive jurisdiction over constitutional issues, and would almost never have original jurisdiction in any case presented over the legality of impeachment proceedings.

It takes a long time to reach SCOTUS and cases can become moot

A case reaches the U.S. Supreme Court, if at all, by being litigated in a trial court and then an intermediate appellate court (possibly with en banc review in a federal appeal, or an intermediate state appellate court and then a state supreme court) first. This takes time, and many impeachment issues are time sensitive.

For example, any issue about the legality of an impeachment proceeding related to the potential removal from office sanction became moot, and beyond the jurisdiction of the courts, in the case of Donald Trump's second impeachment on January 20, 2021. At that point, only the legality of a bar on holding future public offices, if he had been convicted by the U.S. Senate, and if he had sought a future public office anyway, would have been justiciable. Since it takes a long time for litigation to work its way to the U.S. Supreme Court, impeachment issues will often become moot before it can consider them.

Federal courts are barred from considering hypothetical cases

The ban on the U.S. Supreme Court considering hypothetical cases is considered to be a binding rule of constitutional law that is jurisdictional under the "case or controversy clause" of the U.S. Constitution.

Impeached individuals are uniquely unsympathetic but others lack standing

Few people other than the impeached individual would have standing to litigate issues related to impeachment. So, you are left mostly with people whom two-thirds of the U.S. Senate voted to remove from office going to the courts asking to get their jobs back, and an even smaller subset of people whom two-thirds of the U.S. Senate voted to remove from office and a majority votes to bar from holding future public offices, appealing to the courts for relief in litigated cases. People in those shoes are not sympathetic figures. You have to have messed up pretty badly to each such bipartisan scorn. Unsurprisingly, courts are ill inclined to cut them a break in a close case, which makes such people unlikely to resort to the courts for relief.

Answer 3

It depends upon what you mean by “unconstitutional”. They almost certainly would not rule that the Constitution forbade Congress from having an impeachment trial, even if it was something insane like impeaching a new born baby.

Any decision on that front would unduly restrict Congress. If a court can say the process is unconstitutional, then while it’s happening lower courts would have jurisdiction over the impeachment. That is something that is clearly forbidden by Constitution.

What they could rule, is that a Judgement was not constitutionally valid. So, in the case of of our little baby, they could rule that the Judgment was unconstitutional and that baby was eligible to run for whatever office it qualified for. Same thing could happen if they impeached a President, and have someone other than the Chief Justice preside, or added something else onto the Judgement like a fine or jail.

The most likely scenarios for them to rule on is of course a successful impeachment for a former office holder or successful impeachment for actions that took place before holding office. But it’s really unlikely that it will ever happen, because in order to have such a ruling, someone would have to lose, and then appeal. Impeachments are so rare that both losing and having grounds for an appeal is really unlikely. Controversial impeachments are unlikely to be successful, non-controversial impeachments are unlikely to have grounds for appeal.