Back in the early 70's the Detroit carmakers were grinding out junk, crap on wheels: gigantic things with soft balloons for tires which guzzled gas and couldn't take corners much more nimbly than trains. Then there was the 1973 oil crisis, and much larger numbers of Americans bought Japanese and European cars because they used much less fuel, and the word finally got around to such an extent in the US that foreign cars were better, that the Detroit carmakers were forced to compete. At some point, Ford's official motto became "Quality is Job 1." That might still be their official motto for all I know. Before 1973, quality may have been Job 14 or so. Not that GM, Chrysler or AMC were any better in this respect. They were all able to get away with this because too few American car buyers knew enough about Japanese and European cars to know what they were missing. (In 1973 the Korean auto industry was still in its very early stages.)
How long will it take for word to get around in the US amongst people either agree with the stated goals of the Green Party or actually throw their votes away by voting Green that proportional representation in other countries means that the Greens and socialists and so forth actually take part in governing, that a vote for such parties is a real vote and not merely a protest? Because of proportional representation? How close to 100% will the total of Denmark's energy which is generated by wind, solar and other green technologies have to get before Americans become quite rightly envious of this aspect of Denmark and realize what chumps we've been to put up with oil companies and their mostly-Republican minions?
Or maybe the question is: what sort of a crisis will it take for enough Americans to look around and see what other countries are doing in terms of political representation and and green energy to make a difference in the way the US runs its government and generates its energy, the way it took the 1973 oil crisis for enough Americans to take a look at cars made outside the US to change the way American cars were made? I hope that's not the question.