Gregory's ServerThere is a federal statute, 18 U.S.C. §2383, which states "Whoever incites, sets on foot, assists, or engages in any rebellion or insurrection against the authority of the US or the laws thereof, or gives aid or comfort thereto, shall be fined under this title or imprisoned not more than ten years, or both; and shall be incapable of holding any office under the United States."
DOJ might have prosecuted Trump under that statute, but they didn't, and now it's too late.
@Bobblegagger @urbanfoxe
I should add, I'm not a lawyer, and I have no idea how feasible it would have been for DOJ to obtain a conviction under 18 U.S.C. §2383. Trump obviously did what the statute says, but that doesn't necessarily mean it's easy to get a conviction in court.