A few reasons actually:
1) The global elites want her to be President. In a recent issue of the Economist magazine (globalist mag) who else but the hilderbeast was on the cover, with other globalists including Merkel, Obama, and the good old Pope. Was Bernie Sanders on the cover, no, was Ted Cruze on the cover, no. Was Trump on the cover, no. But Hilary Clinton was.
They know that Clinton being President will pretty much be a 3rd and fourth term continuation of Obama's Presidency - open borders, free trade, getting US into more and more debt.
2) The election will be completely rigged, just like Trump said it will be. Even if voting machines get mostly Trump votes these machines can be easily hacked into with passwords like 12345, and have the machines be in favor of Clinton.
I believe part of the reason Obama is flooding the US with illegals (practically bring people from across the boarder) is so that they will vote for Clinton and as a bonus be long time Democrat voters.
All the people on welfare will vote for Clinton. This will be a HUGE voting block.
3) The Mainstream news networks are all in the tank for Clinton.
Anyways thats just what i think. Even if Trump does win the election, he won't win it, if that makes sense. Just look at 2000 and how Bush stole it from Gore.