The Senate shall choose their other officers,[1] and also a president pro tempore,[2] in the absence of the vice-president, or when he shall exercise the office of president of the United States.

[1] These are similar to those of the House. (See p. 131.)

[2] The president pro tempore is chosen from among the senators.  Being a senator, he can debate and vote upon any question.  He cannot, of course, give a “casting vote,” because that would virtually give him two votes.

The president pro tempore serves during the pleasure of the Senate, or until the expiration of his senatorial term.

It is the general practice for the vice-president to vacate his chair at the beginning of the session, to permit the Senate to chose a president pro tempore, so that if during vacation the vice-president should become president, the Senate might not be without a presiding officer.  Until recently this was quite important, for the president pro tempore of the Senate was next to the vice-president in the succession to the presidency.  But the succession has been changed. (See p. 190.)

Clause 6.—­Impeachment.

The Senate shall have the sole power to try all impeachments.[1] When sitting for that purpose, they shall be on oath or affirmation.[2] When the president of the United States is tried, the chief Justice shall preside;[3] and no person shall be convicted without the concurrence of two-thirds of the members present.[4] Judgement in cases of impeachment shall not extend further than to removal from office, and disqualification to hold and enjoy any office of honor, trust or profit, under the United Sates;[5] but the party convicted shall, nevertheless, be liable and subject to indictment, trial, judgment and punishment, according to law.[6]

[1] For the mode of conducting impeachments, see pages 131 and 331.

To have impeachments tried by a court of law would be unwise for several reasons:  In the first place, judges should be kept free from political contests, in order that they may retain the proper judicial frame of mind.  In the second place, judges are appointed by the executive, who may be the one impeached.  Lastly, a judge is himself subject to impeachment.

[2] To enhance the solemnity of the occasion.  The British House of Lords when sitting as a high court of impeachment is not under oath.  But courts usually are.

[3] The vice-president, having interest in the result, would be disqualified.  The chief justice, from the dignity of his station and his great experience in law, seems the fittest person to preside on such a grave occasion.  Except in this single instance, however, the vice-president presides in trials on impeachment.

[4] In an ordinary court, the verdict of the jury must be unanimous.  To require similar agreement in this case would be to make it next to impossible ever to convict.  To allow a bare majority to convict would be to place too little protection over a public officer.