Three or four parties could easily happen in the USA of they'd change their electoral system. FPTP system and lack of culturally divergent regions (like Scotlan

Three or four parties could easily happen in the USA of they'd change their electoral system. FPTP system and lack of culturally divergent regions (like Scotland in the UK) is the reason there are no third / fourth powers. If, say, half of Congress were elected by party lists, there'd be a lot of political diversity fast.