In the United States Senate, if there is a tie in a vote, the vice president breaks that tie. According to the senate.gov website, the vice president cannot vote except when breaking a tie.

Is there any practical difference between this system, and a system where the vice president just gets a single vote like each senator does? If a vote ends up 50 "for" and 50 "against", and the VP breaks the tie by voting "for", is that any different than if the VP just voted normally, and the vote ends up 51 for and 50 against? To put in in another perspective, after the VP breaks the tie and you have a vote of 51 "for" and 50 "against", couldn't any one of those 51 "for" votes be said to be the tie-breaking vote?

In another situation, if the vote is 40 "for" and 60 "against", then the VP doesn't have a tie to break so they don't vote. But even if they did vote normally, it would just be 41 "for" and 60 "against", so the results would be the same.

Is there a situation where there is a meaningful difference between the VP breaking a tie, and the VP getting a vote? Or is it simply a matter of procedure/process; not wasting the VP's time by voting except when a tie-breaker is needed?

  • 3
    Accumulation's answer corrects your math: the current system is definitely different from the VP getting one whole vote, but it's less different from the VP getting half a vote. DonHosek's answer and its comments point out some situations where "an extra half-vote" could change the outcome, but where the current system doesn't permit the VP to use their "half-vote" because the situation is not a 50/50 tie. Commented Dec 10, 2020 at 17:50
  • Probably inherited from the (at the time) somewhat impartial Speaker of the US House of Commons Commented Dec 11, 2020 at 18:26

4 Answers 4


Under normal circumstances, there is no difference. However, the Senate is not always full - Senators die or resign, or simply fail to make it to a vote. These were even more common situations when the Constitution was written. In situations where the number of voting Senators is not an even number, then granting the VP a full normal vote could produce a tie when there wouldn't have been one without it (50 to 49+1, for example).

What do you do when your tie breaker causes a tie instead of resolving it? Much simpler to just not involve the VP unless it becomes necessary.

As @apnorton points out in a comment, it's also relevant to determining whether the 2/3 supermajority needed in a few specific cases (such as overriding a veto or removing an impeached person from office) has been reached. If the vote is at 66+VP for/34 against, that's a failed vote, since 67 is passing. If the VP voted normally, it'd still require a 2/3 majority, just out of a slightly larger pool. With the current size of the Senate, it requires 67 votes for such a majority regardless of whether there are 100 or 101 votes cast. (At 102, it'd require 68.)

That said, the VP was originally intended to preside over the Senate, and thus have influence on the result even without an actual vote. Day-to-day, that responsibility is delegated to a President pro tempore, who in turn delegates it to another Senator under most circumstances. Modern Senate rules also don't provide the VP an opportunity to speak during a debate, further limiting this role, but it does Constitutionally exist.

  • 1
    I do wonder if it's actually "normal" for all 100 senators to vote, or if it's more common that at least one is absent (for whatever reason), possibly having the senate end up with an odd number of voting senators present.
    – ilkkachu
    Commented Dec 10, 2020 at 12:36
  • 7
    @ilkkachu: The votes recently taken by the Senate are available in a handy list on their website. It looks like the vast majority of the recent votes taken do not involve all 100 senators. The most recent vote that did have 100 senators voting appears to have been Amy Coney Barrett's confirmation vote in October, which makes sense given the importance of that vote. Commented Dec 10, 2020 at 14:16
  • 2
    Don't forget about instances where a 2/3 supermajority is required, too --- if you're one vote off of a 2/3 majority, that's not technically a tie, so having the VP vote could cause a difference there.
    – apnorton
    Commented Dec 10, 2020 at 16:10
  • @apnorton - Good call. I've added that.
    – Bobson
    Commented Dec 10, 2020 at 17:04
  • perhaps "ideal" instead of "normal"
    – JCRM
    Commented Dec 11, 2020 at 8:20

The biggest difference is that by forcing the VP to vote only in case of a tie, there is no way a VP's vote can create a tie. This is a pretty substantial practical difference. If it were an ordinary vote, it would be possible to create a tie any time that an odd number of Senators were involved in the vote.

  • 1
    "it would be possible to create a tie any time that an odd number of Senators were involved in the vote": this is incorrect would only be possible to create a tie if an odd number of senators voted and the difference in votes for each side is exactly one. For example, if 99 senators voted, with 51 on one side and 48 on the other, the difference is three, and it would not be possible to create a tie.
    – phoog
    Commented Dec 10, 2020 at 8:10
  • 5
    @phoog Depends on how you view "possibility". :) Indeed, a 1 vote difference is possible any time an odd number vote. OP may have assumed there is always a 100-person vote and therefore no way for this to happen - this is what I meant to highlight. Commented Dec 10, 2020 at 15:00

Politically, there is an important difference in that generally speaking, the VP can dodge taking a stand. The senators are expected to vote on everything that comes before the senate, even if that vote is "present" (and voting "present" on a bill does entail political consequences).

Also, I don't think the VP is included in quorum calculations. If the VP were a normal voting member, then the question of whether they should be included would arise. There's also the fact that if there were to be an odd number of senators for some reason, then under the current system the VP does not vote. If the system was that VP always votes, then an odd number of senators could result in a tie with no tiebreaker. As it stands, the VP can be thought of as having half a vote: enough to break a tie, but not enough to create one.

  • 1
    The third sentence should say "...if there were to be an odd number of votes cast...," not "...of senators...." If there are 99 senators, but one does not vote, and the rest split 49 to 49, then the VP can vote.
    – phoog
    Commented Dec 10, 2020 at 8:16

I would imagine a significant part of this is not wasting the VP’s time, although there is also the case of procedural votes, particularly cloture, where a VP vote would make a difference even without being a tie-breaker (e.g., if the vote for cloture were 60 for and 40 against, if the VP were to vote against, the motion for cloture would fail),

  • 2
    Actually cloture requires 3/5 of the number of senators, so the threshold is 60 regardless of the number of votes cast, though I suppose the rule wouldn't be written that way if the VP could normally vote. But the principle described here would apply for example to a veto override, since 67 to 33 exceeds the 2/3 threshold while 67 to 34 does not.
    – phoog
    Commented Dec 10, 2020 at 8:04
  • @CGCampbell the only job contemplated for the VP by the constitution is to preside over the senate. The constitution merely makes an explicit rule of a practice that had arisen in Westminster as a matter of convention.
    – phoog
    Commented Dec 12, 2020 at 7:17
  • Furthermore, the VP only votes when there is an equal number of votes on both sides of a question. If the vote is 60 to 40, the VP cannot vote. (This comment may not be particularly relevant to this question, but it is relevant to another question that links to this answer.)
    – phoog
    Commented Mar 6, 2021 at 19:43

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .