“Banana republic” is specifically a term referring to countries that are puppets of the United States on behalf of commercial interests (the trope-naming example being Gautemala on behalf of United Fruit Company); in the absence of an imperial power pulling US strings on behalf of that powers’ commercial interests which dominated the US economy, it would be hard for the US to be reasonably described as going the direction of a “banana republic”.

What it is more going the way of a major power resenting a weakened position in the world falling into authoritarian and/or kleptocratic nationalist dictatorship leaning on the propaganda of restoring national greatness, somewhere between Hitler’s Germany and Putin’s Russia, which is a very different situation than a banana republic.