Whether the president should be charged does not have to depend on whether he instigated the attack on the Capitol or stopped shortly before the instigation. (A sentence I never expected.) A reasonable reason for impeachment is rather simpler and publicly known.
Last Wednesday, Trump publicly called on Vice President Pence to interfere in the vote count. He claimed that pence and pence alone could “send it back” to states for different voters to be nominated. And he complained bitterly when Pence failed to do this:
Suppose Pence had listened. For example, suppose he had announced from the podium when Arizona’s voting began, “I am sending this certificate back to Arizona to nominate new voters.”
That would have been incontestable. The twelfth amendment required pence, “in the presence of the Senate and the House of Representatives, [to] Open all certificates “at what point” the votes will be counted. “Whether states should have nominated different voters has been the subject of numerous legal disputes, which have now been resolved. Whether these certificates were the authentic certificates listing the votes of those voters who had nominated them was not contested even by the President. And whether or not the electoral census law gave Congress the power to vote on objections, Pence had no power to decide the matter for himself. For Pence to interfere in the count and hope to be able to stay in office after his term was up, that would be clear Violation of his constitutional obligations.
In these circumstances, it was even incontestable for the President to ask the Vice-President to commit a criminal offense. Refusing to leave office is a great felony or misdemeanor, if any. And asking for a major crime or misdemeanor is itself a major crime or misdemeanor even if it is unsuccessful.
Many people viewed Trump’s efforts as stupid and the hopes he had of staying in power despite the vote in the electoral college as frivolous. But other people took them seriously. So the Capitol was attacked. The president’s faithlessness has killed five and his impeachment is long overdue.