Each party has a Party Leader. If that party wins a majority, the Leader is PM by default. If there is a coalition of two (or more) parties required to make up a government, (usually) the Leader of the plurality party is the PM. 

I suspect the direct election of a President is more the issue when comparing the attributes of a Republic to that of a Parliamentary Democracy.  If you read between the lines in the Federalist Papers, the issue of electors was more a matter of preservation of issues associated with owners of private property than political parties.

As long as we have a FPTP popularly elected President, our politics will converge towards a two-party system. If we could ht a reset button and start with five or more parties of relative equal strength and support, within two or three Presidential elections, we’ll have two major parties getting 90–95% of the vote and the others will be hangers-on. This is because we don’t have a parliamentary system where the Prime Minister is elected by the parliament. The quest for a majority of the popular vote is what will continually push us towards a two-party system. That doesn’t mean a third party can’t rise up and supplant one of the major two, but if such a third party rose, then I predict that within two Presidential elections, we would be back with two parties again, though the alignments (and names) of those parties will likely have shifted.

By definition, those who have won the electoral lottery are less susceptible to pressure — it’s not going to do one iota of good to try and push Obama more to the left after he wins re-election (and, for our friends on the right, if you imagine that you can pull Romney more to the right — you need to cut back on your medications).

Historically, the way to pull the political landscape one way or the other is to split from the existing party structure, build support, and, with your base of support, induce one of the existing parties to subsume your policies — or simply supplant a party.  That’s what happened to the Whigs.  Teddy Rooseveldt and the populist movement of the late 19th century.  To a great extent, FDR coopted the great swell of socialism in the 30’s into the Democratic party (and largely eviscerated it along the way).

That’s what has happened to the Republican party in modern times.  Once the party of the wealthy and the Bourgoisie, it’s now the party of right-wing religion, racism, and randroids.  Whether the new structure of the Republican party is stable and capable of electoral success remains to be seen — whether it will continue its success or will wither away, to be replaced by something new (or maybe old, like the historical Republican party retaking power.  But the economic imbalance currently going on in the country militates against a recovery — why should the immensely wealthy give up their new ability to control the narrative and frame the debate?)

You should know better, being from Minnesota — when the Democratic party in Minnesota, suffering from a hardening of the political arteries due to decades of electoral success, started running candidates like “Skip” Humphrey, whose only qualifications were a history of undeviating loyalty to the Democratic party, the party was shaken up (and, IMO, improved) by the appearance of two phenomena — Paul Wellstone and Jesse Ventura.  Now it’s the Republican party in Minnesota which is saddled with political dinosaurs like Quist and Bachmann (whose sell-by-date has passed, although the idiots in her district may well send her back for another term of grandstanding while doing nothing for them).

No, if you want the political landscape to change, you won’t do it through unwavering support for a politician or party that has gained success through pursuit of a particular set of policies — it is the nature of many-headed beasts like political parties and corporations to strictly hew to the path that got them where they are. 

If you want to change direction, find somebody going your way and join them, and convince as many people as possible to do the same.

In a state in which taking one’s vote away from the better of two candidates won’t affect the outcome, a vote on principle will neither help nor hurt the immediate election.

But contributing to the candidate of the major party who is closest to your view helps both the short-term and long-term practical concerns.

I agree with you that we need at least three major parties. I’d be happier if we had four or five, and had a more parliamentary system. I don’t we’ll get there in our lifetimes however — particularly not for us old farts. I think it would take a major shift in national consciousness. One way or another, I think the Republican Party is going to have a major schism within the next decade, and that could be the impetus toward acceptance of additional parties.

Oh, and I was 90% Obama and 90% Stein. 56% Texas voters.

I strongly believe that the rise of what is today a “minor” party will fundamentally transform American politics and break the partisanship and gridlock that seem to dominate current political discourse. That’s why I’m voting for Dr. Stein. I could be persuaded to vote for Governor Johnson as well.

Still, I’m a pragmatist, and in the 10 states (probably four — Ohio, Virginia, Ohio and Ohio) where the election is actually contested, I want to do some good. Unlike many Republicans believe, I’m not willing to commit voter fraud, so sending the Obama Victory Fund some buckage is the next best thing.

(Has anyone done a calculation of how much a vote is “worth”? That is, what size of contribution to a political campaign equals one vote? I bet the relationship is not linear, so that Adelson’s $1M does not get 1 million times as many votes as my $1.)

Maybe in my retirement I will move from purple state to purple state, knocking on doors and working GOTV for my favored candidate.

One hopes that such a protest vote advances one’s causes, because it expresses concern for a particular issue or set of issues. Unfortunately, most of our culture is not that subtle. The only real numbers that most people look at are the numbers for the major candidates. To use the current example, if Obama’s numbers slip, most Americans will assume it is because Obama (and, therefore, progressive policy) has become less popular.

We saw this in the health care debate. Many progressives were unhappy because Obamacare doesn’t go far enough. We wanted universal single-payer. But the polls showed either support or opposition, and the enormous number of people who opposed it because it wasn’t Medicare For All got lumped into the people who want insurance companies to rule the world and it was expressed as the percentage of people who support or oppose health care reform.

The long term impression then is that Americans want to go back to what we had before.

Votes for minor-party candidates — and subtle opinions about complex issues — are ignored. Going beyond the present election, a protest vote is a vote against the policies you intend to support, because it takes support (even symbolic support) away from the major candidate who is closest to those policies.

If neither major party is to your liking on particular issues, the way to advance those issues is to throw loud support behind someone who is closest and put pressure on them while they are in office to address those issues. Anything else falls prey to our culture’s tendency toward black-and-white-ism.