How many Senate votes does it take to pass a bill?

Quick Answer

It takes a simple majority, or at least 51 votes, for the Senate to pass a bill and send it to the House for consideration. There are 100 senators, so 51 affirmative votes are the minimum needed. Exceptions to the simple majority rule include invoking cloture and overriding presidential vetoes, which both require supermajorities of 60 votes and 67 votes, respectively.

Background on the Senate

The Senate is the upper chamber of Congress. Along with the House of Representatives, it comprises the legislative branch of the federal government.

There are 100 senators serving staggered six-year terms. Each state elects two senators, regardless of population. Currently, the Senate is split 50-50 between the Republican and Democratic parties, with Democratic Vice President Kamala Harris breaking ties.

The Senate’s responsibilities include passing legislation, conducting impeachment trials, ratifying treaties, and confirming presidential appointments and Supreme Court justices. While bills can originate in either the Senate or House, revenue-related bills must originate in the House per the Constitution.

How a Bill Becomes a Law

For a bill to become law, it must pass both chambers of Congress and be signed by the president. Here is the general legislative process:

1. A bill is introduced in either the House or Senate.

2. The bill is referred to the appropriate committee for review. The committee may hold hearings and make revisions.

3. The committee votes to send the bill back to the full chamber for consideration.

4. The full House or Senate debates the bill and may add amendments.

5. The House or Senate votes on the bill.

6. If the bill passes, it goes to the other chamber to repeat steps 2-5.

7. If the House and Senate pass different versions, they must reach a compromise through a conference committee.

8. Once the House and Senate pass identical bills, the bill goes to the president.

9. The president signs the bill into law or vetoes it.

10. If the president vetoes, Congress can override the veto with a two-thirds vote in both chambers to pass the bill.

Senate Voting Rules and Procedures

The Constitution sets out basic voting rules and procedures for the Senate. But others have been established through tradition and parliamentary rules. Some key things to know:

Simple majority – Most bills and resolutions need just a simple majority to pass. This means at least 51 out of the 100 senators need to vote ‘yes.’

Three-fifths majority – An exception is that most bills and resolutions need a three-fifths majority of at least 60 votes to invoke cloture. This limits consideration and ends any filibuster.

Two-thirds majority – Constitutional amendments, veto overrides, convictions in impeachment trials, and treaty ratifications require a two-thirds supermajority of at least 67 votes.

Quorum – A simple majority of 51 senators must be present for votes. If less than a quorum is present, the Senate will adjourn or a call of the absent senators can be issued.

Veto-proof majority – While 67 votes are needed to override a presidential veto, a two-thirds majority in both chambers is considered a veto-proof majority, forcing the president to sign the bill.

Unanimous consent – For expediency, the Senate often fast-tracks uncontroversial bills through unanimous consent. One member can object to block this.

When is a Supermajority Needed?

While most Senate bills need just 51 votes to pass, there are a few key situations when the bar is raised to a three-fifths or two-thirds supermajority.

60 votes – Ending debate and filibusters

One of the Senate’s hallmark features is the filibuster, an attempt to delay or obstruct a vote on a bill. Filibusters occur during the debate stage and can be ended through a cloture motion.

Invoking cloture requires three-fifths of senators, or 60 votes, to agree to limit further consideration and end the filibuster. This higher threshold means the minority party can block votes on controversial legislation.

60 votes – Senate rules

In addition, 60 votes are needed to change or amend any of the Senate’s standing rules, including procedures around the filibuster. This means senators themselves cannot adjust rules with a simple majority vote.

67 votes – Constitutional amendments

A two-thirds supermajority is needed in both the House and Senate to pass any constitutional amendment for ratification by the states. Constitutional amendments have historically been very difficult to pass.

67 votes – Conviction after impeachment

If the House votes to impeach an executive or judicial official, two-thirds of senators must vote to convict and remove them from office in an impeachment trial. A simple majority is not enough.

67 votes – Treaty ratification

The Constitution specifies that treaties with foreign governments must be approved by two-thirds of the Senate before taking effect. The House does not vote on treaties.

67 votes – Veto overrides

If the president vetoes a bill, Congress can override that veto with a two-thirds vote in both the House and Senate. This allows a bill to become law over the president’s objections.

When Bills Need Less Than 51 Votes

In some cases, passing a bill in the Senate requires fewer than the 51 vote simple majority.

Voice votes

For completely uncontroversial bills, the presiding officer will simply ask for vocal yeas and nays from senators, rather than a recorded vote. If no senator objects, the bill is passed by unanimous consent without a formal vote count.

Unanimous consent

Similarly, routine legislation is often fast-tracked through unanimous consent agreements. If no one objects, measures can skip several steps and pass with just a quick vote.

Budget reconciliation

Budget reconciliation bills regarding revenue and spending can pass with just a simple majority, and cannot be filibustered. However, strict rules limit the contents of reconciliation bills.

Vote Thresholds in the House vs Senate

While both chambers play a role in passing legislation, there are key differences between House and Senate voting rules and thresholds.

Vote Type House Requirement Senate Requirement
Simple majority on bills 218 votes 51 votes
Supermajority to change rules Simple majority 60 votes
Ending filibuster N/A 60 votes
Constitutional amendments 290 votes 67 votes
Veto override 290 votes 67 votes

Some key differences:

– The Senate has higher vote thresholds overall, including for filibusters, rules changes, and veto overrides. This empowers the minority party.

– Without filibusters, the House can pass legislation with just a simple majority.

– The House has 435 members and the Senate 100 members, so their simple majority thresholds naturally differ.

– While both chambers need two-thirds votes for constitutional amendments and veto overrides, the House has a higher 290 vote requirement.

Cloture Votes

One way to dig deeper into Senate voting patterns is to look at cloture votes over time. Cloture votes restrict debate and can end filibusters, so they indicate which bills faced obstruction.

The table below shows the number of cloture votes held each Congress since 1971, according to Senate records:

Congress Years Cloture Votes
92nd 1971-1973 4
93rd 1973-1975 22
94th 1975-1977 38
95th 1977-1979 61
96th 1979-1981 84
97th 1981-1983 80
98th 1983-1985 96
99th 1985-1987 111

Key takeaways:

– Prior to 1970, cloture votes were very rare. Only 49 cloture votes occurred from 1917 to 1970.

– Use of the filibuster and cloture votes increased dramatically starting in the 1970s and 1980s.

– In recent Congresses, over 100 cloture votes per session have become commonplace. The 115th Congress from 2017-2019 had 298 cloture votes.

– The rise in cloture votes indicates bills now routinely fail to get 60 votes and face obstruction tactics.

Cloture Votes by President

Another perspective on cloture votes is to look at trends by president over time. This table summarizes cloture vote tallies during each recent presidential administration:

President Years Cloture Votes
Nixon 1969-1974 4
Ford 1974-1977 75
Carter 1977-1981 208
Reagan 1981-1989 359
H.W. Bush 1989-1993 196
Clinton 1993-2001 329
W. Bush 2001-2009 442
Obama 2009-2017 564
Trump 2017-2021 298


– Cloture votes remain relatively constant from presidency to presidency. They reflect broader political polarization, not just White House agendas.

– H.W. Bush saw a dip in cloture votes after Reagan’s tenure. But the number shot up again under Clinton.

– Obama faced record cloture votes during his presidency. This shows the depth of Republican obstruction.

– Trump’s cloture votes per Congress are similar to Reagan’s. But with fewer total years, his aggregate is much lower.

– Both parties engage in filibuster tactics when they are the minority party in the Senate.

Senators Who Vote Against Their Party

While political parties enforce voting unity, senators do occasionally vote contrary to their party’s positions. Some recent examples:

– Democrat Joe Manchin of West Virginia regularly votes against his party on environmental and social issues reflecting his state’s politics.

– Republicans Susan Collins of Maine and Lisa Murkowski of Alaska are moderates who have broken with their party on abortion rights, healthcare, and other issues.

– Republican Rand Paul of Kentucky has voted against the majority Republican position on issues like defense spending and surveillance laws out of libertarian principles.

– A group of centrist Republican senators sank a 2017 ACA repeal bill despite pressure from their party.

– Maverick Republican John McCain famously voted against ACA repeal in 2017, allying with Democrats.

Such cross-party voting is rare today compared to past eras. But it can have major implications for close votes.

Senate Independents

The partisan makeup of the Senate occasionally includes independent senators who do not caucus with either major party. They have more freedom to vote across party lines.

Current independent senators include:

– Bernie Sanders of Vermont, who aligns with Democrats but ran for president as an independent democratic socialist.

– Angus King of Maine, another independent who caucuses with Democrats.

Historically, high profile Senate independents have included:

– Joe Lieberman of Connecticut, a former Democrat who blocked his party’s initiatives.

– Jim Jeffords of Vermont, whose 2001 party switch from Republican to independent flipped the chamber’s control.

– Wayne Morse of Oregon, who left the Republicans in 1953 and later opposed the Vietnam War.

– Harry Byrd of Virginia, a conservative who refused to endorse Democrats despite winning on the party ticket.

With zero or just a few independent senators at any given time, they have been able to play outsized roles in swing votes.


In the Senate, most legislation can pass with just a simple majority or 51 votes. This allows the majority party to approve bills when voting in unison.

However, supermajority thresholds come into play for cloture votes to limit debate and end filibusters, amending Senate rules, overriding presidential vetoes, ratifying treaties, and approving constitutional amendments. These 60- and 67-vote thresholds empower the minority party.

Despite its lower profile, the Senate holds equal power with the House in passing bills. But higher vote thresholds give individual senators and the minority party in the chamber tremendous ability to obstruct the majority agenda. Understanding Senate voting rules and trends in cloture votes and party unity sheds light on how bills move through Congress.

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