Over the summer, I did a multi-part series called "Zero-sum politics" about Trump's view of everything as a zero-sum game, his consequent inability to accept "losing," and how that might translate into problems like claims of a rigged election should Clinton win. Here's the executive summary.
Trump's basic nature is to think of things in zero-sum terms. That makes losing unthinkable to him, and he must explain away losses. A rigged election is a convenient way to do so. However, he is also probably too lazy to act in any serious way on that. Should he try, he would be limited by the extent to which his supporters believe in the basic constitutional framework of the US system rather than existing leaders, and there is a big difference. Even so, real movements require ground-level leaders who haven't emerged and aren't likely to emerge. Republican leaders, such as they are, have incentives to try to stop Trump anyway, but they must begin to act before the election to quash talk of "unskewed polls" and such.
For those who want to read the whole series, here are the links.
Part I
Part II
Part III
Part IV
Part V
Part VI
And, since it's Sunday, here's a bluegrass-y cover of a 90's alterna-crap song that I always hated. This, I like.