I'm going to give you a realistic path on how Trump can win and you tell me what you think. While you are worried about demographics and the current standing of things, Trump has a lot of cards he can play to get the edge on Hillary.
1. He runs a competent campaign in the general
Lets just assume from here on out he's able to keep up his anti-PC image without saying additional things that can be seen as racist/sexist. There will of course be some petty attempts to label him as racist and sexist, but those won't stick unless he says something substantial.
2. He effectively attacks and keeps repeating Hillary's biggest flaws
This is also very easy to imagine. He can start by reminding Americans how anti-2nd amendment she is and that he will do everything in his power to protect that right. That alone will be enough to unite the Republican base. He can also point out how she favors amnesty which proves she cares nothing about stopping illegal immigration. If he plays his card right on this topic he can make her look too forgiving and weak which would significantly hurt any female candidate. This gets Republican women to support him and also wins a lot of moderates.
Not to mention we might see more terrorist attacks during this election cycle. Trumps rhetoric seems much more committed to defending our country from attack while Hillary and most Democrats seem a bit too patient on the issue.
3. Republican endorsements
This one is probably the most important for Trump. If Trump can get Kasich to be his VP he wins Ohio hands down, and in the process, wins over some independents and democrats. Kasich has said he definitely won't be VP but if Trump is the deal maker he says that he is, I don't see it being too farfetched. Then you have Rubio, who already seems to be softening up to Trump. If he gets Rubio's endorsement, it not only makes him look extremely diplomatic, but it might put him over the edge in an already close Florida race. I seriously doubt he gets Jeb's support, but if he did that would ice the state.
So, if Trump gets Ohio and Florida, and of course all traditional red states, all he needs is either Pennsylvania, Michigan, Virginia or any combination of small swing states (New Hampshire, Iowa, Nevada, Wisconsin, or Colorado). That is entirely doable because of a few factors. Michigan is in a terrible state, with crumbling infrastructure and having their jobs outsourced. Trump will appeal to the workers there. Virginia will have less black vote than in 2008-2012 and is home to a lot of uneducated white men, prime Trump territory. The rest have high populations of white voters and are true wildcards.
4. He uses demographics to his advantage
The Republicans know Hispanics are a lost cause. They also know black voters won't show up for Hillary like they did for Obama. If the black vote returns to what it was for Kerry in 2004, Hispanics could vote 90% in favor of Hillary (Obama had 76%) and have a 20% increase from 2012 and it still won't flip one state. Therefore, his entire road runs through the white women vote.
He obviously has no chance of winning women, but if he can lessen the blow to previous election levels, he will win. That is simply because he will win men by a large margin. Many men, especially older ones, will be hesitant to elect a woman as Commander in Chief. And this is not sexist, it's a natural concern because men are the biological protectors of the family. Trump earns the woman vote by breaking character and showing his softer side. He is already making amends with Megyn Kelly which will make for a huge interview. He can hammer home how he believes in Planned Parenthood and is open to keeping abortion legal, while still being against it. This makes him look strong, but also negotiable and fair. He can also get his wife and daughter more in the mainstream spotlight, who are both exceptional women and reflect very favorably on him.
So all in all, Trump has a very fine road he must to walk down to win. He's certainly not the favorite, but it's going to be a lot closer than people think it will be. Hillary's legal troubles could also play a factor, but he can only worry about what's in his control.