Here's why I think not -
First, as far as Brexit is concerned, although the pro-Brexit "leave" vote was trailing the anti-Brexit "stay" vote in the lead-up to the U.K. referendum, the two were closer (just a few points in the polls) than Trump is now to Hillary Clinton in the United States (he's ten or more points behind in many states, including some swing states).
But those numbers aside, the electoral system in the U.K. is very different from what we have in the U.S. In the U.K., everyone voted once, pro or against, Brexit. The potential for surprise that goes against the polling is much greater in that kind of system than in the U.S., in which the Presidential election takes place months after the conclusion of a series of primaries.
Why is that important? Well, not to be too cynical about it, but our U.S. system gives more people more time to come to their senses, and not vote their first impulses. Indeed, Trump won the primaries because people were indeed voting their first impulses, which they didn't have all that much time to think over, and in the Republican Party were not all that antithetical to Trump in any case. But Americans including Republicans now have had lots of time to find out about Trump's treatment of women, his refusal to say he'll abide by the election results, and lots of other very disturbing factors not many people knew about during the primaries.
Nothing is impossible in elections. But John Milton and Thomas Jefferson's belief that if truth is in the market place of ideas with all the falsity, sooner or later a majority of rational human beings will recognize it, seems to be at holding sway in the United States, where the truth about Trump has had time to get known.
We all have to vote, but I'm looking forward to watching Waldo where he belongs, not in the White House but on Black Mirror's darkly satirical television.