You can look it up. D still has a 4 seat majority if R gets all the remaining undecided elections.
Several reasons:
A lot of them are just RINOs. They want to take the path of least resistance and rock the boat.
If they vote to overturn the election, they risk death threats and assassination attempts by Antifa. We have, unfortunately, lost rule of law to the angry mob.
A lot of them would prefer to see Trump gone so things can go back to "normal".
Even if it's vetoed, then PA sends two sets of electors, and then Congress decides. If nobody in Congress defects, Trump/Pence win. (R holds a slim lead in state delegations. If a few R in deep red states flip, Trump doesn't win if the election goes to the House.)
The outcome less likely to lead to a civil war is giving it to Biden.
Election results is overturned - The left has the numbers to burn down every city.
Election result stands - I don't see the right doing much besides posting on the Internet.
A lot of Western countries have birth rates below replacement.
In Muslim countries, the culture is to have as many kids as you can. What happens is a Muslim might have 10 children. 2 stay in the country, and the 8 go to invade western countries as migrants.
3:1 on AOC being the next president. I don't see that happening.
If they weren't going to give the nomination to Sanders, it certainly isn't going to be AOC.
Also, the trend is for incumbents to get a bye for their party's nomination. That means Biden or Harris gets the D nomination in 2024 (unless Trump wins).
The senate could wind up 51-49 (counting Romney as R).
If Romney flips, it would be 50-50 and Harris would be VP tiebreaker. Then the Democrats can do whatever they want, eliminate the filibuster, pack the court, make Puerto Rico a state, give illegals citizenship, etc.
There actually is a dirty trick they could try.
The formula for electoral college is "House Seats" + "Senate Seats".
The size of the House is not specified in the Constitution. The Constitution just says a minimum size of 30,000 per district. Current law fixes the size of the house at 435, making it around 800k people per district.
They could just change the size of the House to 4350. Then all the big states would get 10x the votes in the electoral college.
Some of the protest leaders get paid. The useful idiots are mostly criminals who are eager for the opportunity to assault people or destroy property, and get away with it.