personally, this is my take.
Trump is a lifelong dem. He loved 2006 when dems/pelosi took over, even wrote her a love letter.
Trump donated to clinton - not romney - in 2008 primaries. And she lost. At that point, he decided to shit on obama for the next 7 years. He was the biggest voice for the birthers - making it a walking joke eventually.
Trump has gone very easy on hilary. He's been much harder on republicans. "Her hubby cheated" is way nicer than "little marco, lyin ted" he used on fellow republicans.
He was an outright dem into his 60s, then magically changed the minute obama won the nomination. Think about that. in 2016, he's been harder on bernie than on hilary. He's been shitting on past republican leaders, presidents, candidates, calling them losers with really nothing to gain. He's breaking up with every ally possible, starting feuds within his own party.
He's trying to lose so his buddy - front row at his wedding, and to whom he donated tens of thousands in 2008 primary, can win this election. George will said it, Jeb said it, many have said it. I've been saying since 2011 that trump is a dem plant.
Remember ALvin Greene in SC a few years ago? outright plant in the senate race - and it freakin' worked. He was dirt poor, facing sex charges, but magically showed up with $10k to register and run to siphon votes and resources.
Trump is a dem plant, and a lot of people believe it. "I want to face hilary" was an honest moment from donald trump.