On August 23, 2021, on the Volokh Conspiracy, Professor Eugene Volokh wrote:
Now I suppose one could argue that the Senate President pro tempore would be able to cast two votes, when the VP is Acting President of the U.S.: One in his capacity as Senator, and one in his capacity as Vice-Vice-President. But apparently that has never been the understanding.
The issue of multiple voting by a Senate President Pro Tempore has certainly been discussed over the years. The most relevant Constitution text is not entirely clear on this point.
U.S. Const. Article I, Section 3, Clause 4: The Vice President of the United States shall be President of the Senate, but shall have no Vote, unless they [the senators] be equally divided.
U.S. Const. Article I, Section 3, Clause 5: The Senate shall choose their other Officers, and also a President pro tempore, in the Absence of the Vice President, or when he shall exercise the Office of President of the United States.
There are two ways to read Clause 4:
The Vice President of the United States shall be President of the Senate, but [the Vice President] shall have no Vote, unless they [the senators] be equally divided.
The Vice President of the United States shall be President of the Senate, but [the President of the Senate] shall have no Vote, unless they [the senators] be equally divided.
In other words, does the ostensible grant of a vote on equal division apply exclusively to Vice Presidents (or to Vice Presidents when acting as Senate President), or does it apply more generally to all Senate Presidents, including Senate Presidents Pro Tempore?
In debate, on January 7, 1792 on a proposed presidential succession act, in conformity with U.S. Const. Article II, Section 1, Clause 6, William B. Giles, a congressman from Virginia, stated:
[T]he person [the Senate President Pro Tempore] contemplated by the bill [to succeed to the presidency in the event of a double vacancy], will be authorized to vote on all questions as Senator, to take the vote of the Senate as [Senate] President pro tem. (perhaps to give the casting vote on equal division) and to discharge the duties of President of the United States. [House of Representative of the United States / Friday, January 7, The Mail / Claypoole’s Daily Advertiser (Philadelphia, Penn.), Jan. 10, 1792, at 2.]
I think it fair to conclude that the constitutional text is ambiguous. It is certainly true that multiple voting offends modern sensibilities. The more difficult question is whether those modern sensibilities are in tune with how people understood parliamentary chambers to function circa 1788. See generally Margaret A. Banks, The Chair’s Casting Vote: Some Inconsistencies and Problems, 16 U.W. Ont. L. Rev. 197 (1977). Modern uniformity in regard to state and federal legislative practice flows from the fact that as the country expanded westward, state practice followed what became settled federal practice. However, during the colonial period and under the Articles, there was considerable variation in parliamentary practice across the colonies and then the states. See, e.g., John F. Burns, Controversies Between Royal Governors and Their Assemblies in the Northern American Colonies 320 (1923) (“[Prior to 1733, Governor] Cosby [of New York] took part in the deliberations of the Council while acting in a legislative capacity. Thus as a member [!] of the Council he had one vote, as executive he had final veto power, and in case of tie he cast the deciding ballot. Always two, and sometimes three, votes were at his command.”); Mary Patterson Clarke, Parliamentary Privilege in the American Colonies 232 (Leonard W. Levy ed., Da Capo Press 1971) (1943) (explaining that “in some colonies, the governor frequently sat with the council, and there was some difference of opinion as to whether he was or was not a member of it”); Leonard Woods Labaree, Royal Government in America: A Study of the British Colonial System before 1783, at 160 (N.Y., Frederick Ungar Pub. Co. 1958) (1930) (noting that royal governors “not only often attended the legislative council but presided there”); id. (noting that “less commonly” royal governors asserted the right to vote in the legislative council, “either as a regular member, or as the presiding officer in case of a tie”); id. at 164–65 (noting that the law officers of the Board of Trade opposed the claim of New York’s Governor Cosby to a vote in the legislative council, but their advice and recommendation was not put into force by the Privy Council); William Smith, A Comparative View of the Constitutions of the Several States with Each Other and with that of the United States tbl.1 & n.n (Philadelphia, John Thompson 1796) (“Connecticut. [Governed under the] Old Colonial Charter of Charles II [of 1662]. unaltered, except where necessary to adapt it to the Independence of the United States. . . . Governor, as Presid[ent] of the council, and the Speaker of the House, have each a vote, besides a casting vote.”).
Seth Barrett Tillman, Tillman on Volokh on the Senate President Pro Tempore, New Reform Club (Aug. 25, 2021 4:57 AM), <https://tinyurl.com/37y5sv4b>;