We should all be concerned the Trump supporters are already calling the election rigged. This is a classic move by conspiracy theorists and paranoid delusional maniacs to make claims that cannot be refuted without helping "prove" the conspiracy. What's worrying is the scale of these claims and the fact Trump himself is amplifying them.
But here's another problem: he's not entirely wrong. It's clear the media is in the bag for Clinton and trying to help her win. We know this by the leaked emails and how CNN provided her debate questions in advance of her debate with Bernie Sanders. This would be akin to a teacher telling one student the test questions before a test.
We also know the number one issue where Trump has more popular support than Clinton is immigration. This is the issue he has ridden to the nomination and could ride to the Presidency. No one is talking about it -- not in the press, not in the debates, etc. The press and the Democrats know the issue is a loser and seeks to make the election about Trump's personality and not the issues. Trump loses on personality, but could win on issues.
And it's not as if this just came about on this election. People will erroneously make the argument, well shouldn't the "responsible" press be in favor of Clinton because Trump is such a volatile person? First of all - that's not what we want from the press, although they've taken it upon themselves to play that role. Go back to Romney and McCain who now look like centrist candidates -- and see how the press treated them. They shit all over Romney for being rich, out of touch, racist, etc. They make McCain seem too old with too many health issues to be President.
It reminds me of when lunatic gamblers lose and claim the refs are in the bag, but it turns out Tim Donaghy WAS is the bag. This doesn't make the gamblers right, it makes both sides wrong.