Indeed. If we consider the mean standard of the entire world the USA is most definitely left-wing.
You're right. I'm being ethnically/economically discriminatory by only factoring in the "first world". If we include SA, Africa, the Middle East, and most of Asia, the US probably jumps to the top 10% of the world for progressivism/liberalism.
I think it's a bit erroneous to define right wing and left wing as "democratic" and "undemocratic", as you seem to be doing. Most of the countries in the Middle East besides the likes of Saudi Arabia or the UAE were originally, and to a certain extent are today, pretty left wing, thanks to all the Arab Nationalist/Socialist groups like the Ba'ath Party. Being right wing generally means that you either support a social hierarchy or social inequality, left wing meaning the opposite.
That said, liberalism ranks highly in the USA, but that in itself can be a bit of a centrist ideology. On one hand liberals tend to support social equality, but they sacrifice some of their options to achieve that equality (such as totalitarianism) in order to increase personal freedom and such.
If you compare the nations of Africa and their governments, you will likely find that left-wing parties have often done quite well, even if they end up being undemocratic corrupt bastards. If you look at Europe, Christian social democracy or social democracy in general is all the rage. In east Asia, generally liberal or left wing parties are doing well in Japan, China, Mongolia and Cambodia. South Korea and Taiwan both follow models of democracy which closely model the USA. The grey areas here are Myanmar and Thailand. Thailand is currently governed by a populist party (which can mean a lot, considering the Red Shirt fiasco) and Myanmar's government is currently quite conservative, although it is currently softening up. If one looks at South America, one will again find socialism, democracy, left wing politics and liberalism flourishing in Venezuela, Brazil, Suriname (less so), French Guiana, Paraguay, Uruguay, Guyana, Bolivia, Ecuador, Argentina (to an extent), Colombia, Peru, Chile, all except the Falkland Islands (from what I can see) because most of their politicians are entirely non partisan, so it's quite difficult to tell.
So even if you do look across the world at the political alignments of national governments, you will mostly see left wing politics, democracy and liberalism. On paper at least, because these countries often go off the deep end.That's not to say that right wing totalitarian countries don't exist - Saudi Arabia for example, but these are, thankfully, the minority.