A lot of people who say they are voting for Johnson (or Stein) will, in the final picture, decide not to vote . Those that will vote will vote for Clinton more than they would usually. These are mostly GOP voters after all. So in all probability the polls are exaggerating Trump's chances.
Sure, but I doubt this effect will be worth more than a few points.
Anyway, I'm tired and with a sh**tty WIFI connection in a bus so a question: Am I right in thinking that 1984 was the only contested election in US history where one candidate won all 13 of the original colonies?
1936 works as well.