There always must be a presiding officer. Either the President (the VP of the United States) or the President Pro Tem, in the President’s absence. But the voting restriction only applies to the President of the Senate. The President Pro Tem is just a regular senator who has been chosen to have an administrative role. He always has a vote, whether presiding at the time or not.
On a tie vote, the motion fails. A simple majority is reached only when the yeses outnumber the noes.
They can be impeached, and a Senator once was, although expulsion obviously provides a simpler remedy. The reason to employ impeachment instead of (or in addition to) expulsion is to implement the “disqualification clause” (forbidding the convicted party from holding any office of “honor, trust, or profit” under the United States).
Senator William Blount was impeached and expelled in 1797, and charges remained pending before the Senate even after his expulsion. After further investigation the Senate dismissed the charges, in 1798, without saying why.
True, Blount was impeached by the House. However, it’s not so clear that the impeachment was legal. In fact, it was argued during his trial that the House does not have the power to impeach members of Congress. The Senate or courts never ruled on it one way or the other and the House has never again tried to impeach someone.
My wild guess would be that if it were tried today, the courts would shoot it down.
Zev Steinhardt
Doesn’t the Presidential Succession Bill simply say – or at least defualt to in the absence of other instructions – that succession goes through the cabinet secretaries in the order of creation of the posts?
Of course someone other than the President Pro Tem can be presiding over the Senate in the absence of the VP. You don’t think the PPT never goes back home to campaign do you? But yes there must be a presiding officer by Robert’s Rules. Not sure how the Senate works, the the presiding officer should not vote. (S)he shouldn’t even participate in discussion of the motion under Robert’s Rules.
So if the vote comes up 48-48. The pesiding officer may cast a vote to break the tie. (S)he certainly cannot do so if (s)he has already voted.* If the vote is 48-47, the presiding officer should not cast a nay vote to make it a tie defeating the motion for lack of a majority.
*Aside – the rules of the MIT Science Fiction society allow this. In fact they allow the President to vote in the event of a tie. “Event of a tie” is interpreted as yeas = nays + or - 1 actually. That is, the tie may occur as a result of the President’s vote. In which case he can vote again. And it’s a bit more complicated than that since there are three votes “yea” “nay” and “chicken” so if the vote total is 1, 6, 6, a tie exists and the Preseident can vote yea, since a tie sitll exists, the president can again vote yea until the motion passes.
Actually, it’s a bit more complicated than that since the president holds two offices by tradition, president and skinner and each is entitled to vote.
Well that’s all by 30 year old memory you understand – thngs may have changed – and don’t worry, by conventio, the society never decides important things. 
In fact the PPT almost never presides over the Senate. Presiding is considered a chore which is farmed out to junior senators on a rotating basis.
And in fact they don’t debate; if the presiding officer wishes to speak, he/she will wait until his/her stint as president is over. Because the job is so trivial and transitory, however–with the job often changing hands while a roll call is in progress–the presiding officer doesn’t abstain from voting.
Before or after noon? 
No. The Presidential Succession Act (codified at 3 U.S.C. § 19) still does not include the Secretary of Homeland Security. The act establishing a new executive department customarily adds the department head to the line of succession at the end, so that (as OldGuy notes) the line in fact extends through “the cabinet secretaries in the order of creation of their positions.” But the act establishing the Department of Homeland Security omitted such a provision – through oversight, I am told by a friend who worked in the Attorney General’s office at the time, but who knows. There was some draft legislation in 2002 or 2003 that would have added the Secretary of Homeland Security to the line of succession, but not at the end – following the Secretary of Defense, IIRC.
Huh? There is neither a Department of Environmental Affairs nor a Secretary of Environmental Affairs. The EPA Administrator does meet with the Cabinet in the Bush administration, but that status depends on the President’s pleasure, since the President can invite whomever he or she likes to Cabinet meetings. The only executive-branch officers in the statutory line of succession are heads of statutorily established executive departments, whose status does not change from administration to administration.
To wander even further off the subject, I’ve heard that a proposal has been made to even further modify the Presidential Succession Act to include governors, in order of state populations, after the cabinet officials. The idea is that if the aliens nuke Washington in a sneak attack and wipe out the entire federal leadership, we’d still have somebody around to take the oath and order a counterattack (or to sign the surrender order).
California Governor Arnold Schwarzenegger, like Secretary of Commerce Carlos Gutierrez and Secretary of Labor Elaine Chao, would be ineligible because of his foreign birth. So Texas Governor Rick Parry would be the 17th choice to run the country.
As I would have hoped the alien invasion would have made clear, it was a hypothetical scenario of extreme improbability, and I invented a new cabinet-level office because I was unsure if the Secretary of Homeland Security had in fact been added to the law or not. The intent was to suggest the improbability of a Vice President who does not want to be President.
Little Nemo, I started a thread on that last summer. I still think it’d be a good idea:
http://boards.straightdope.com/sdmb/showthread.php?t=332688&highlight=bayh+washington