One of the stupidest (and persistent) ideas out there has been that The Internet has led to people being stuck in their little community bubbles, seeing only the information they want to see, exposed only to things that please them.
Anyone who thinks that has never found the "turn internet on" button on their personal computer machine. The internet is one big nonstop argument. Anyone who uses the book of faces gets to see the horrible things people they used to be friends with have to say about the world, and the equivalent of those email forwards your annoying uncle used to send you from his AOL account.
Anyway, when I say Trump can win, what I usually mean is: Trump can win, and this shouldn't be a big surprise. A large chunk of your fellow Americans, including your friends and relatives, will vote for him. This shouldn't be a surprise because those of us who have paid attention have known all along that this was what the Republican base wanted, and a big chunk of Republicans will vote for anyone with an R after their name (same as true of Democrats, but to a much lesser extent).
I know this because I read the internet, and sometimes it's horrible.