In US elections, candidates are elected individually. However, most recent elections track closely with each other in terms of partisan vote choice.

The reason this is relevant is in the past, there were local parties with large differences to cater to the ideological lean and social circumstances of their areas. But that has largely disappeared and state parties are mostly arms of national parties.

Congresspeople who vote party line usually win primaries unopposed or very easily but do not do so enough usually face primary challengers. Examples:

  1. Pro Trump impeachment Republicans are facing primary challenges.
  2. Joe Manchin and Kyrsten Sinema are facing heavy criticism for not voting for certain more ambitious Democratic proposals.
  3. Some Senate Republicans are criticized for voting for Biden bills especially the infrastructure one.

Party discipline is the idea that if most of a political party's base/members favors a certain legislation or idea, every elected representative should support it because it is their duty. The United States does not have this directly.

But I want to know if this seems to be developing in the sense that members of Congress who buck the party trend like Krysten Sinema are criticized, mostly by their own party. I'm thinking about primary elections being the biggest mean to enact party discipline. The big difference is that this type of what could be thought of as party discipline is usually enacted by voters not simply leaders of parties.

  • Related: Why doesn't the US have party discipline?. Oct 15, 2021 at 14:22
  • Party discipline is alive and well. Manchin and Sinema are special cases -- effectively Republicans but for tactical reasons, they obtain more leverage for their sponsors by pretending to be Democrats. The Democratic leadership goes along with it, because even if those two voted with Republicans every time, at least Schumer would still get to be Senate Majority Leader, giving Democrats ability to set the agenda in the Senate. More generally, "party discipline" in the sense of primarying the "undisciplined" is a mechanism wielded be centrists against progressive D's and libertarian R's.
    – Pete W
    Oct 15, 2021 at 18:40
  • 1
    @PeteW And wouldn't work in Manchin or Sinema's cases anyways, because a party-line-towing primary challenger who managed to beat them would get crushed in the general election. Dems would lose the seat for nothing.
    – Ryan_L
    Oct 15, 2021 at 19:20
  • What makes party discipline "formal"? Are there laws in the UK regarding this? Do MPs sign something that enables party discipline that US Congresscritters do not? Oct 15, 2021 at 20:13
  • @AzorAhai-him- See this question. Briefly: in the UK, political parties are essentially private organisations. If an MP wants to represent a party, the MP has to toe the party line. If they don't, they can be suspended or expelled from the party, and will have to run as an independent in the next election. Oct 16, 2021 at 15:15

2 Answers 2


As mentioned in the comments, it is far from clear what "party discipline" means. One reasonable definition would be that the formal party apparatus can effectively direct party members on how they should act in their elective office. Two key words here:

  • The formal party apparatus would be the DNC/RNC or something like that, as opposed to the President or the Majority and Minority Leaders in Congress or individual charismatic leaders. When the Congressional leadership directs their caucus members, that's about caucus discipline ...
  • Effective control means more than meaningless letters of censure. Often control over election candidacies is the ultimative control instruments -- a defector could run again as an independent, but not on the party ticket.

That second point weakens party discipline in the United States. In the primaries, candidates have to convince registered voters rather than the party activists or the party apparatus. So the two sides in the United States may be getting more partisan, but that isn't what some other parts of the world understand as party discipline.

  • Last point seems to happen sometimes. en.wikipedia.org/wiki/Lisa_Murkowski "After losing the 2010 Republican primary to Tea Party candidate Joe Miller, Murkowski ran as a write-in candidate and defeated both Miller and Democrat Scott McAdams in the general election. She is the second U.S. Senator (after Strom Thurmond in 1954) to be elected by write-in vote. Murkowski was elected to a third term in 2016." Oct 15, 2021 at 18:52
  • @Fizz, that's not quite what I meant. Murkowski wasn't thrown from the ticket by "the party establishment" of the Republicans, she fell infighting between different segments of "the party base."
    – o.m.
    Oct 16, 2021 at 9:38

There is strong party discipline in the US it is just that it doesn't always get applied for every office for their voting habbits. This happens either from being removed from positions or a simple censure.


The Wyoming Republican Party voted Saturday to formally censure Rep. Liz Cheney, the No. 3 Republican in the House, for her vote to impeach former President Donald Trump in the latest example of a state GOP punishing lawmakers who have bucked the former President.


House Republicans voted Wednesday to remove U.S. Rep. Liz Cheney from her leadership position after her continued pushback against former President Donald Trump’s baseless claims of voter fraud in the presidential election.


The House of Representatives has voted to strip Republican Rep. Marjorie Taylor Greene of her committee assignments, following uproar over her past incendiary comments and apparent support of violence against Democrats.

  • The Taylor Greene example isn't party discipline, it was a House motion only supported by 11 Republicans. Oct 15, 2021 at 20:22

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