While Nancy Pelosi threatens to withhold articles of impeachment passed Wednesday night by the House, Harvard Law Professor Noah Feldman says that President Trump isn't technically impeached until the House actually transmits the articles to the Senate.

Feldman, who testified in front of the House Judiciary Committee's impeachment proceedings earlier this month, argues in a Bloomberg Op-Ed that the framers' definition of impeachment "assumed that impeachment was a process, not just a House vote," and that "Strictly speaking, "impeachment" occurred – and occurs -- when the articles of impeachment are presented to the Senate for trial. And at that point, the Senate is obliged by the Constitution to hold a trial."

If the House does not communicate its impeachment to the Senate, it hasn’t actually impeached the president. If the articles are not transmitted, Trump could legitimately say that he wasn’t truly impeached at all. That’s because “impeachment” under the Constitution means the House sending its approved articles of to the Senate, with House managers standing up in the Senate and saying the president is impeached. As for the headlines we saw after the House vote saying, “TRUMP IMPEACHED,” those are a media shorthand, not a technically correct legal statement. So far, the House has voted to impeach (future tense) Trump. He isn’t impeached (past tense) until the articles go to the Senate and the House members deliver the message. -Noah Feldman

Pelosi, meanwhile, won't transmit the articles until the Senate holds what she considers a "fair" trial.

Roughly modeled after England's impeachment procedures, the framers in Article I of the constitution gave the House "the sole power of impeachment," while giving the Senate "the sole power to try all impeachments."

Article II outlines says the president "shall be removed from office on impeachment for, and conviction of, treason, bribery, or other high Crimes and Misdemeanors."

There's more:

But we can say with some confidence that only the Senate is empowered to judge the fairness of its own trial – that’s what the “sole power to try all impeachments” means. If the House votes to “impeach” but doesn’t send the articles to the Senate or send impeachment managers there to carry its message, it hasn’t directly violated the text of the Constitution. But the House would be acting against the implicit logic of the Constitution’s description of impeachment. A president who has been genuinely impeached must constitutionally have the opportunity to defend himself before the Senate . That’s built into the constitutional logic of impeachment, which demands a trial before removal. To be sure, if the House just never sends its articles of impeachment to the Senate, there can be no trial there. That’s what the “sole power to impeach” means.

In closing, Feldman says "if the House never sends the articles, then Trump could say with strong justification that he was never actually impeached," adding "And that’s probably not the message Congressional Democrats are hoping to send."