There's a few other similarities between America and the USSR also worth noting. Off the top of my head:

• Both were founded by radical revolutionaries who were the Far-Left of their respective time periods.
• Both were 'proposition nations' in which being considered part of the in-group involved appearing to adhere to certain mental states (attitudes, beliefs, ideas, etc.)
• Both essentially have the same values (extreme emphasis on freedom and equality) but merely interpreted them in different ways (e.g. USA was traditionally about equality of opportunity and negative liberty; USSR aspired to equality of outcomes and positive liberty).
• Both remind one of the importance of academic fields to politics (the Marxists routinely drew upon philosophers like Kant and Hegel and upon 'bourgeois' economists like Ricardo and Smith; America similarly owes a debt to Locke).

There are also some significant differences:

• USSR started off as socioculturally and economically Far-Left and tried to move Rightward in all respects as it aged (e.g. tried to demolish the family until around 1926 when the government decided there were too many war orphans for them to deal with, Stalin put an end to tolerance of abortion, Gorbachev put additional restrictions on alcohol production in the early 1980s), USA started off as culturally conservative but is lurching socioculturally Leftward.
• The USSR was rapidly decentralizing in all respects (while China only decentralized its economy). American power is going in the opposite direction (away from the states and towards the Federal Government).

Unwillingness to serve in the military (and rapid alteration of the military's demographics) also has parallels with the Roman Empire (the Roman military was already minority Roman before 100 AD).