1) There is a delay between events and the polls. The effects of the Mexico trip and Phoenix speech will show up later this week. Expect Trump to drop, especially in states with large latino populations. Like Florida.
2) Some analysis of polls suggest that Trump really hasn't gained anything in the last few weeks, but some Clinton supports are now saying they will vote for Stein or Johnson. Third party voters tend to move back to their primary candidate when it comes the day of the election.
3) Remember Gore won the popular vote, but lost the electoral vote. I don't think that will happen this time. But even if the polls tighten, I just don't see any viable path for Trump to win the electoral vote. Trump would have to win New Hampshire, Nevada, Florida, Ohio, North Carolina, and Iowa. No way he could win them all.
4) Let's say Trump gets to 270 electoral votes. What are the chances that one is a faithless elector? The electoral college are actual people who meet in December to vote for the President and Vice President, and they are not bound to the candidate they pledged to. The electoral college was specifically designed to prevent crazy shit from happening, like electing someone so unqualified for the job. If enough electors choose not to vote, or vote for someone else, then the election would go to the (new, post election) House of Representatives, which is currently controlled by Republicans, and they can select anyone they want. Then, if I remember my high school civics class correctly, the Senate gets to select the vice president.
https://en.wikipedia.org/wiki/Faithless_elector
