Excerpt:
"The first and only time a Cabinet-level official was impeached occurred during the presidential administration of Ulysses S. Grant. Grant's Secretary of War, William W. Belknap, was impeached in 1876 for allegedly receiving payments in return for appointing an individual to maintain a trading post in Indian territory. Belknap resigned two hours before the House unanimously impeached him, but the Senate nevertheless conducted a trial in which Belknap was acquitted. During the trial, upon objection by Secretary Belknap's counsel that the Senate lacked jurisdiction because Belknap was now a private citizen, the Senate voted 37-29 in favor of jurisdiction. A majority of Senators voted to convict Secretary Belknap, but no article mustered a two-thirds majority, resulting in acquittal. A number of Senators voting to acquit indicated that they did so because the Senate did not have jurisdiction over an individual no longer in office. Notably, although bribery is explicitly included as an impeachable offense in the Constitution, the impeachment articles brought against Secretary Belknap instead charged his behavior as constituting high crimes and misdemeanors. Bribery was mentioned at the Senate trial, but it was not specifically referenced in the impeachment articles themselves."
Exactly. That’s real thin gruel for the impeachers to lap up as their precedent for moving forward on a retroactive presidential impeachment case.