The Senates process to impeach former President Donald Trump officially began on Monday, when the House formally delivered articles of impeachment to the upper chamber.

Theres little debate about the central facts of the matter. Trump spent months telling his supporters the election was stolen, then on Jan. 6, riled up a mob that later stormed the U.S. Capitol to try to stop the electoral count and overturn the election results. In the House, 222 Democrats and 10 Republicans voted to impeach Trump for incitement of insurrection. Even several Senate Republicans have said what Trump did was wrong, although some argue it was not an impeachable offense.

But Republicans are still expected to try to stop Trump from being convicted not by arguing hes innocent, but by arguing its too late.

Trump left office on Jan. 20, and the trial is set to begin in February. He will be the first ex-president to face such a trial.

Republicans have already presented what is likely to be a central argument for not convicting Trump. They argue that the Constitution does not allow for the impeachment or conviction of people who no longer hold office.

[T]he Senate lacks constitutional authority to conduct impeachment proceedings against a former president, Sen. Tom Cotton (R-Ark.) said in a statement on Jan. 13 . The Founders designed the impeachment process as a way to remove officeholders from public office not an inquest against private citizens.

Last week, I opposed the effort to reject certified electoral votes for the same reason fidelity to the Constitution I now oppose impeachment proceedings against a former president, Cotton added.

Why are we doing this when the president is out of office? Sen. Joni Ernst (R-Iowa) said on Jan. 19 . When asked if she thought such an impeachment was constitutional, she added, I dont think it is.

I believe an impeachment trial of a former president is unconstitutional and would set a very dangerous precedent, Sen. Ron Johnson (R-Wisc.) tweeted on Jan. 21 . There is no provision in the Constitution for holding such a trial over a former president who is now a private citizen.

Sen. Rob Portman (R-Ohio) called the constitutionality of a late Trump impeachment a serious issue on Monday, according to CNNs Manu Raju . As I look at the Constitution it says that impeachment is for removal and keeping someone from running for office again, not or, he added.

But this wouldnt be the first Senate impeachment trial of an official who no longer held office. While there may be disagreement among constitutional scholars on whether such a late impeachment is possible, there is precedent for such an action.

And as Senate Majority Leader Chuck Schumer (N.Y.) argued on Monday, ignoring Trumps impeachment would set a precedent of its own.

The theory that the Senate cant try former officials would amount to a constitutional get-out-of-jail-free card for any president who commits an impeachable offense, Schumer said.

Can Former Officials Be Impeached?