It's not the whole country, it's the perfect storm of the absolute worst people who spent the last few decades working to seize power combined with the death throws of late stage capitalism. The political and economic elite in America (and most other countries) have merged and corrupted each other beyond redemption, but the ultra capitalist systems of the US means there are few if any effective checks to their power. In a properly functioning country the government checks the power of corporations via regulations and laws and in turn is checked by the will of the public but in the US the incessant corporate propaganda has convinced a depressingly large chunk of the population that government regulations are inherently bad and that everything works better when corporations are free to do whatever they want. That combined with the absolutely blatant bribery and corruption in US politics means that corporations control the US government rather than the other way around.

The whole thing worked for a little while while the corporations were at least pretending to somewhat care about consumers and things like anti-monopoly regulations, but now that Trump has shown the government is very loudly and publicly for sale to the highest bidder they've all gone mask off and are just doing whatever they want. The problem of course is that they're also run by morons that either don't see the cliff they're all collectively racing towards or just don't care because they're planning to bail out with all the profits while the greater US economy burns.

Ultimately this is the sprouting of the seed that was planted back in the 50s from an amalgam of the cold war anti-communism propaganda and the latent racism that was never properly dealt with following the civil war.