538 has him back at 45.3 Points among likely voters. That is almost a 5 Point surge over the last 2 month. In the Last 2 weeks alone he gained way over two Points. Given the trend he will sit at around 45.5 Points tomorrow. That is only 0.5 below is 2016 starting point and within his margin of error. I am sorry to break the news for You but Trump has this thing locked up. Yes Biden will win the popular vote by a wider margin than Clinton. But Trump has enough support in the bag to secure the Electoral College.
Trump has never cracked 50 percent, making him the only president in history to have that distinction.
As for your false claim that Trump was 5 points lower two months ago, he was at 47 percent just before the first debate. Then Trump showed his ass at the debate and his popularity plunged.
History shows that incumbent presidents usually receive about the same percentage of the popular vote as their approval rating.
So look for Trump to receive only 45 percent of the popular vote.