The Constitution of the United States provides in Article I that the “House of Representatives shall have the sole Power of Impeachment” and that the “Senate shall have the sole Power to try all Impeachments.”

By passing articles of impeachment, the House has impeached the President. The Senate trial is being held up because House Speaker Nancy Pelosi refuses to send the articles of impeachment formally to the Senate and to name House managers to begin the process. She may withhold the articles until she is assured that the rules of a Senate trial are, in her view, fair — that they will include, among other things, an opportunity for Senate Democrats to call witnesses of their choosing and introduce documents they consider relevant to the proceedings.