Section 1. The house of representatives shall have the sole power of impeachment. The concurrence of a majority of all the members shall be necessary to an impeachment. All impeachments shall be tried by the senate, and, when sitting for that purpose, the senators shall be upon oath or affirmation to do justice according to law and evidence, and shall be presided over by the chief justice of the supreme court. Should the chief justice be on trial, or otherwise disqualified, the senate shall elect a judge of the supreme court to preside.