If you want to see what Alexandria Ocasio-Cortez and her kind will do to the Democratic Party, look at the disruption Donald Trump did to the Republican Party. Crude insulting tweets to emotionally attract people fed up with the other side is right out of Trump’s playbook. Your idea of a liberal lost their home in the Democratic Party long ago and the radical left is locking the door to keep them out.
We would need a viable third party for the people you think of as liberals. As I respectfully say to my 90+ year old mother, the Democratic Party of your youth no longer exists and never will again.