comment: >
  
  An unpopular party cannot win an election.  If they win, they're ipso facto popular.
context: The closest comparison I can think of is En Marche  ! From France, but I don’t think that would be a proper comparison. >
  
  There have been a few party systems in the United States over the course of its existence.
  Usually, it plays out like this:
  
  The United States faces a split over an important difference in policy (Constitution vs Articles of Confederation, banking and tariffs, slavery, Civil Rights)
  The parties start defining themselves over this central issue (Federalists vs Democratic-Republicans, Whigs vs Democrats, Democrats vs Republicans, Democrats vs Republicans vs Southern Democrats)
  Once a new central issue arises, either a new party springs up and subsumes one of the two existing parties, as the previous split no longer adequately defines the party coalitions, or one of the two existing parties incorporates the issue into their platform and absorbs the new party.
  
  The best example of this is the Whigs, a party that differentiated themselves from Democrats on economic grounds, but who didn't really have a reason to exist when economic differences became less important than views on slavery.
  In general, since both parties are already pretty ideologically diverse, its very difficult to make a meaningful third party run >
  
  I'd say Ross Perot's candidacy is probably the reason Bill Clinton was able to defeat George Bush Sr.  
  I don't know if Perot actually intended to win or if he intended to be a spoiler candidate, but he seemed to siphon more Republican votes than Democratic votes, thus resulting in a Democratic win. >
  
  When it happened in Canada it didn’t work out very well.  I can’t source it for you at the moment, but if you research ‘Canada Elects NDP’ it should pop up. They were and are always the 3rd party underdogs.  They won the election and were basically caught with their pants down. >
  
  I believe you may be talking about Bob Rae’s NDP government in the province of Ontario, not all of Canada. The NDP has never formed a national government but it has  been in government in 6 out of 10 provinces at one time or another. >
  
  Yes, I misremembered that.   Thanks.  I did remember the controversy but not the specifics. >
  
  The USA has a third party that is small and that is the Libertarian Party. It’s best if we don’t let them win.