Do not believe any polls where one of the choices is controversial. We've seen it with Brexit, Trump 1st time and 2019 General Election.
The reality is people are not stupid and are hardly going to declare their true voting intentions if those intentions are going to lead to people calling them racist etc. They will however still go and vote for what they believe. You can guarantee that for every newly registered voter on the back of BLM there will also be one who will register to support Trump. Remember he doesn't have to win the popular vote, just the electoral college and can do so with probably as little as 45% of the popular vote as long as he takes the key states. In short this is going down to the wire and we could see some states so close that the military votes arriving from overseas, and 2 to 3 days late, could swing it either way.
Don't look at betting as they work of exit polls and rely on people being truthful. At 9.55pm on Brexit Day, I was stood outside a William Hill packing up my Vote Leave paraphernalia and the girl left the betting office telling me we had no chance and Leave was now 10/1 against! Of course I accepted that and went off to my local count very subdued. By 11pm as the 1st boxes opened I could see that what the polls had said and what people had voted were 2 different things. By 2am, there were Remainers in tears as my local area recorded 57% Leave and similar margins were being shown across the UK.
I'm not fussed who wins in America today as frankly we have enough homeland issues to deal with but to discount Trump based on media bias would be foolish.