"http://tvtropes.org/pmwiki/pmwiki.php/Main/HitlerAteSugar"

No, that is not the point. Hitler eating sugar had nothing to do with his government. Proportional representation did. That's how he came to power. Look it up.

https://en.wikipedia.org/wiki/Adolf_Hitler#Appointment_as_ch...

"Hindenburg reluctantly agreed to appoint Hitler as chancellor after two further parliamentary elections—in July and November 1932—had not resulted in the formation of a majority government."

They had large number of splinter parties, all of whom hated each other's guts, and which were unable to form an effective government. The Nazis were not a majority (no one was), but were a large, well-disciplined bloc. The rest is, as they say, history.

If one reads about Weimar politics, one striking thing is how basically nobody wanted a democracy. The Communists didn't, the Nazis didn't; Von Papen, Chancellor second before Hitler, of the "Centre" Party tried to get the monarchy re-instated, and ruled Prussia effectively as a dictator. Ending democracy was basically the one thing a majority of Weimar politicians could agree on.

A plurality of German voters voted for the Nazis. If Weimar Germany had the US or UK system of government, that plurality of voters might have given the Nazis an outright majority of seats, just as the UK Tories were recently reelected with only a plurality of the popular vote.

What alternative electoral system would have kept the Nazis out of power in spite of their huge lead in vote share in three successive elections?

The Nazis weren't too concerned with legalities

I am not sure what to make of your first point, as it is not clear that we (HN) have a common understanding of what is meant by "fragmented". Is it a government which does not pass laws or spend money on specific programs which different groups oppose for varying reasons, or would that be a unified opposition? Would fragmented government pass a great many laws and spending programs with no unified goal, to appease disparate interest groups, or would this be a coalition?

>Distinction without a difference. Even if the focus is on the candidates, they're all firmly partisan with little variation.

Does it matter whether the politicians are partisans unified in party goals? It seems that in the USA, politicians frequently go against their own parties, relative to other countries. Is partisanship in favour of non-party aligned interest groups part of what you perceive as a problem? Please describe a non-partisan politician, party, or system.

Lastly, I think we can all agree that a single anecdote does not make the case for or against the PR system, though it does show that PR is not a sufficient condition for stable and everlasting democracy.

The rigid party discipline of the Republican party (in Congress) is starting to look like a temporary aberration. It was caused by a period of unusually strong party control over campaign finances. For a couple of decades there, Congressional leaders were able to strongly prevent Congressmen from being re-elected if they bucked the party.

Ironically, I suspect SuperPACs are contributing to the decay of Republican cohesion -- the party has lost its strong control over re-election. At this point the only thing Republicans in Congress can agree upon is that they dislike anything they suspect a Democrat -- especially the President -- of liking.

As for Democrats, Will Roger's famous quote is something like "I am not a member of any organized political party. I am a Democrat."