If Trump's impeached, then why can't a Senate trial start now?

Call me old-fashioned or naive, but I think my job is to explain what the U.S. Constitution actually means, no matter who likes it or doesn't. That led me to explain recently that under the Constitution as it was understood by the framers and as it still should be understood today, impeachment isn't complete when the House votes to impeach.

Constitutionally, impeachment becomes official when the House sends word of that impeachment to the Senate, triggering a Senate trial.

Impeachment was originally understood to take place when someone from the House formally impeached the president "at the bar of the Senate," which meant a member of the House formally stated to the Senate that the president (or judge, or other officer) was impeached. That practice lasted from the late Middle Ages until 1912. Since then, the House has instead sent a written message to the Senate stating that the House "has impeached" the defendant, a message that triggers the trial procedures in the Senate.

Both versions, old and new, depend on the House officially communicating the fact of impeachment to the Senate. That communication has always taken place in short order after the House voted to impeach. The reason lies in the core element of what impeachment is by its very nature: a prosecution by the House that takes place before the Senate. If the message is not sent and the trial is not prosecuted, there is no genuine impeachment in the constitutional sense of the term.

Until a few weeks ago, no one, to my knowledge, has ever suggested that impeachment could be complete even if there is no communication to the Senate. And no historic example of this new idea has been brought forward in the current discussion. This issue isn't merely theoretical or "academic" in the pejorative sense. It has major political implications for the current standoff between Speaker of the House Nancy Pelosi and Senate Majority Leader Mitch McConnell.

According to the longstanding understanding of impeachment, Pelosi has some modest leverage over the Senate trial. With the authority the House has given to her, she can control when impeachment officially occurs. Constitutionally, the Senate can't try Trump until she triggers the trial by sending a message about impeachment to the Senate. The Constitution gives the House the "sole power" of impeachment; and impeachment means the power to initiate and conduct a prosecution in the Senate.

But if Trump has already been impeached by the House vote, then Pelosi has zero leverage, because the Senate can start the trial right away, without waiting for the House to initiate or conduct the prosecution. After all, the House only has the power to impeach. If it has already executed that power, then the ball is already in the Senate's court. The Senate has the sole power to try the impeachment.

Sure, the Senate's rules say the trial starts "when the managers of an impeachment shall be introduced at the bar of the Senate." But that's because the Senate rules understand impeachment in the traditional sense, to require communication from the House and commencement of a trial. If the brand-new theory is right, however, the Senate can just amend its rules and start the trial now. McConnell, not Pelosi, would then control the trial's timing.

Evidence that official impeachment entails communication to the Senate can be found in every single historical source that discusses impeachment. Here's Thomas Jefferson describing impeachment in England in the manual he created for the House of Representatives: "The general course is to pass a resolution containing a criminal charge against the supposed delinquent, and then to direct some member to impeach him by oral accusation, at the bar of the House of Lords, in the name of the Commons."

And here's the updated House guidance contained in the manual as of now: "The House may vote the impeachment and, after having notified the Senate by message, may direct the impeachment to be presented at the bar of the Senate by a single member, or by two, or five, or nine, or thirteen."

The form of words used by the House ("is impeached") doesn't redefine impeachment to make communication to the Senate unnecessary. Impeachment is now and always has been, by definition, a House-led prosecution in the Senate. Whether in the old days or now, impeachment happens when the Senate is presented with the act of impeachment — which triggers the trial, as the Senate rules say. Anything else would make no sense, because it would allow the Senate to start the trial without the House managers there to prosecute it.

The Florida Supreme Court actually addressed this issue in 1868, after the governor was impeached and claimed he hadn't been because there was no quorum in the Senate. Florida law doesn't control, of course, but the Florida court went through all the sources. It concluded:

"It thus appears by ample precedent and authority, that an impeachment is not simply the adoption of a resolution declaring that a party be impeached, but that it is the actual announcement and declaration of impeachment by the House through its committee at the bar of the Senate, to the Senate, that it does thereby impeach the officer accused, which proceeding is at once recognized by the Senate."

And as Prof. Keith Whittington of Princeton University also points out, the Oklahoma Supreme Court held in 1923 that impeachment is official "when articles of impeachment are duly filed with the Senate and duly accepted and filed by the Senate." The key to both cases is communication. That can happen the old way, at the bar of the Senate, or the new way, by sending over notice of articles of impeachment.

The argument in support of the new definition seems to be that since the House's modern impeachment resolutions, like the one on Trump, say that the defendant "is impeached," impeachment is somehow complete after the House vote. That mistakes a new use of the verb "is" for a new conception of impeachment as somehow already complete after the vote. Yet that conception has never existed constitutionally, because the House has never withheld its impeachment message from the Senate.

It should be pretty obvious that the new theory makes no sense when followed to its logical constitutional conclusion. Everyone agrees that House impeachment triggers a Senate trial. If the House vote alone counted as impeachment, then the Senate would necessarily have the constitutional power to start a trial without the House. That would rob the House of its power to prosecute the trial in the Senate, which is the essence of all impeachment, old and modern alike. The result would be to squander the central value of impeachment. The Senate could distort or ignore the House's case.

What's more, if the House had the power to redefine what "impeachment" means, then the Senate would logically have the power to redefine "trial" to mean something that is not a trial at all. That would similarly rob the House of the power of impeachment, which is the power to prosecute the president in a genuine trial before the Senate.

Those who invented and advocated this made-up theory have done Pelosi a great disservice. Far from giving the speaker greater leverage, their theory would allow the Senate to change its rules and hold a trial now, without the House. The resulting absurdity would do a still greater disservice to the nation, and to the key constitutional procedure of impeachment.

Noah Feldman is a professor of law at Harvard University and was a clerk to U.S. Supreme Court Justice David Souter. His books include "The Three Lives of James Madison: Genius, Partisan, President."