What will happen if Biden wins, best and worst case scenarios

Some polls suggest that Joe Biden is ahead in popularity. And as we saw four years ago, polls are always completely accurate. However, let's assume that Biden does indeed end up winning the elections and becomes the President of the United States. What happens then, realistically speaking? I'll predict the best possible case scenario, the almost worst possible case, and the absolutely worst possible.

Best possible scenario:

• The regressive left becomes completely insufferable, both in social media and in real life, for a month or two, before forgetting about it and moving to something else, to bickering about something else that's "racist" and "transphobic". In other words, after a few months they become the pre-Trump regressive left, continuing their ever-increasing campaign to take over all of society by invading everything.
• Likewise the leftist mainstream media will spend a month or two vilifying Trump and painting him as the worst person who has ever existed, and listing all of his alleged "crimes", and exalting Biden as the Savior of the World, who is absolutely perfect in everything, the second coming of the social justice Messiah. After they get it out of their systems, they go back to making actual news, like in the pre-Trump era.
• Biden will probably be on the public for a while before becoming indisposed, ill, or otherwise incapable of performing his duties, and the Vice-President Harris will step in his place, becoming the first female president (which was the plan of the Democrats all along). Before this Biden, and after it happens Harris, will try to pass some of the laws that they promised and talked about during their campaigns, but like your typical politician they only do a small fraction of them, and even those half-heartedly and with compromises. Maybe they'll restore some kind of half-assed universal healthcare system and try to loosen immigration laws a bit, but overall it will amount to very little and will have a negligible impact on the economy of the country. By the end of her term almost nothing will have been achieved that would have ruined the economy or eroded people's rights.
• Even if Biden does not step down, become unfit or die, SJWs will start demanding him to resign and let Harris become the president (because he's a white old man).
  
• The masked terrorists roaming the streets of cities will continue their terrorism for a while, but it will become less and less common, and they will lose their motivation and impetus to doing it, and best case scenario, it will almost completely stop. At most they will still show up at alleged events organized by conservatives trolling them.

Almost worst-case scenario:

• The radical left, especially but not restricted to the masked terrorists, will take Biden's victory as a signal that gives them carte blanche to hunt conservatives. It will become open season. They will try to start a purge, to engage in "denazification" by assaulting people, shooting people, invading and destroying homes, and so on. Deaths will be counted in the thousands, perhaps even hundreds of thousands. In most cases the police will just watch from the sidelines doing nothing about it.
• Democrat leftist politicians and those in positions of power will either turn a blind eye, make excuses, be extremely slow to react, or outright support this uprising and mass-killing of people.
• The Democratic Party will also try to enact a purge of government, trying to remove all Republicans from it, and any position of power, and essentially trying to make the country a single-party state. They will try to get the majority or even monopoly of all three branches of government so that nothing comes in their way.
• Almost all of the most fundamental constitutional rights will be breached by new laws. The Constitution will be either ignored, amended or even repealed. At a very minimum they will try to come up with excuses about why such-and-such is not against the Constitution because of their own biased partisan interpretation of it. Freedom of speech, freedom of congregation, freedom of the press, freedom of religion, right to a fair trial, right to be secure in one's person, house, papers and affects, and so on and so forth... all gone, or severely diminished.
• Racial segregation and discrimination will become commonplace and even required by law.
• Border control will be completely removed and borders will be completely opened for completely unrestricted unsupervised access by anybody.
• The repeal of the Second Amendment will result in numerous gunfights between citizens and the police, resulting in thousands of deaths.
• Taxes will raise to ridiculous levels. Rich people and corporations will start fleeing the country.
• The economy of the country will completely collapse. The country will split into two or more independent countries. The amount of poverty and suffering will be of unprecedented levels.

Absolutely worst-case scenario:

• In addition to the above, concentration camps modeled after the Soviet gulags. A hundred million people will be massacred. Half of them will be killed in a civil war between the citizens and the communist-fascist stormtroopers, the other half will be killed in the gulags.