Britain has the same first past the post system as America, yet it has serious third parties like the Green Party and UKIP. However, there have only been a few primary elections in the UK and those have only been held recently. They have “leadership elections” but not just anybody can vote in those. The ongoing Labour party leadership election has featured a purge of the membership rolls in order to eliminate supporters of anti-Zionist candidate Jeremy Corbyn.
However, some Republican leaders want to make the system more like that of Britain. According to politico:
Amid mounting concerns about Donald Trump’s candidacy from the GOP establishment, Republican leaders in at least two states have found a way to make life a lot harder for him.
The Virginia and North Carolina parties are in discussions about implementing a new requirement for candidates to qualify for their primary ballots: that they pledge to support the Republican presidential nominee — and not run as a third-party candidate — in the general election.
This tells you that they really fear Trump. They never tried to do anything like this when Ron Paul was running. A certain portion, perhaps even a majority, of the Republican electorate isn’t going to vote for him. But if he gets 40% of the vote and remains the front runner, since the remaining vote will be split between an establishment conservative and a social conservative, he could be a major threat to the GOP establishment. They would then resort to “dirty tricks” to stop Trump. But they don’t want to do that, they want to make it look like a democratic process. They especially don’t want Trump to run as a third party candidate. So I predict that after Iowa and New Hampshire there will be serious pressure on all the non-Trump candidates to drop out. Perhaps the establishment types will coalesce behind Scott Walker, the only candidate who is acceptable to both them and the social conservatives. He will make a weak general election candidate, maybe even worse than Jeb Bush due to his stance on abortion.
I’m hoping that if anything good comes out of this presidential campaign, it will be the development of a serious, UKIP like alternative to the Republican party. America needs it.