Part of me senses the Trump hand is much stronger than being presented in the press, and the polls are garbage or actual attempts to suppress the vote (Which could backfire, since it's as like to make it appear it's in the bag for the Dems so some will stay home, as it is to make Republicans stay home because it's hopeless). There is so much on-line shaming and even doxxing of Trump supporters that I think reluctance to discuss political opinions with strangers is a factor in the polling, I know I have declined a cold calls from a pollsters and I suspect many other Trump supporters have as well. Also the Dems would not be hyping all the civil war, secession, and statehood for PR/DC if they really thought it was in the bag. Trump is much stronger in the area where I live than he was four years ago, Dem support is almost non-existent, but I am in a rural district.
Yet another part is concerned about runaway corruption of the election process with partisan apparatchiks in the Blue strongholds counting the votes, and all sorts of monkey business going on, and worries about the polls perhaps having some validity.
My political contributions have been very few, small, and far between in the past, but this year is an exception, the stakes are just so high I've dropped some major coin (For me) on the WH and a handful of Congressional races (My own state's Senators are not up this year, and my own District is a given for our incumbent (But junior) Congressman.
Pray for the best, prepare for the worst.