U.S. Senate Republicans lost a key argument over the constitutionality of Trump's upcoming impeachment trial. Five Senate Republicans crossed party lines and voted to move ahead with the historic case. But, as 45 Republicans voted against the proceedings even taking place, it seems a conviction of the former president for “incitement of insurrection” is unlikely.

Representative Jamie Raskin (D-MD) leads other House impeachment managers in delivering to the Senate an article of impeachment alleging incitement of insurrection against former President Donald Trump, in Washington, DC January 25, 2021. (Photo: AFP)

The first ever impeachment of a former U.S. president will begin the week of Feb. 8. The U.S. House charged Donald Trump two weeks ago with inciting deadly riots in the Capitol on Jan. 6 when he told his supporters to “fight like hell” to overturn his election defeat.

U.S. Senators took oaths Tuesday to ensure “impartial justice” as jurors in the trial, proceedings that will test Republican loyalty to the former president for the first time after the deadly siege.