I disagree with your second conjecture. The polarization of United States has been largely due to bankcrupting its middle class of its industry, paying off executives(not literally, but due to allure of making cheaper goods in China), social media and Russian interference in the election of Trump.

This is a grand plan of Russia and China to divide western nations, increase internal anti-US propaganda to bolster their authoritarian regimes.

You're pointing to the symptoms, not root cause. And this is exactly what the communist regimes want the west to do - fight against each other. Just wait before Canada get's roped in all of this as well.