I think the major hurdle lies in the differences between the national character of the Russian empire and the USA. The former was comprised of Russia itself, which included a core axis of what even counted as "Russia" in the first place (Moscow, St Petersburg, Kiev), alongside its colonial holdings in central and eastern Asia, all of which directly bordered Russia. The USA is a settler colonial project, started in large part by the British Empire, Spain, France, and the Netherlands sprinking a bit of their own character, built on lands originally occupied by other nations of peoples displaced and killed for its formation, replacing them with foreign white settlers in their place. Therein lies the key difference and contradiction with the USA's national character, in that it gives no representation to those displaced peoples and never did. It would have been a very different national character if indigenous nations were annexed but still recognized and allowed some degree of autonomy in the same way Poland and Finland were under the Russian empire. Instead, these nations were torn out, its peoples killed and rendered extinct, or flung to the far reaches of the most harsh and unlivable parts of the territory and prevented them from leaving. There cannot be any meaningful national character until after decolonization has begun and a new national identity, one no longer gloating and profiting over the graves of countless nations, has been established.