Can of worms -> open...
I've been living abroad in Europe since the 90s. Back then, people in Europe thought the sun shined out of our American asses. Our propaganda of "saving" them in WWI and then WWII worked, and we got credit for the end of the USSR.
By the early 2000s back in the US, the "Reagan Revolution" (including Bush the Greater) and eight years of "globalization" (read: outsourcing of US manufacturing to first Mexico and then China) was starting to take a toll.
The dot com bubble bursting as Monica showed off her blue dress really started things down a path of "What the hell is going on in America?" domestically, but internationally China and India were still weak, and Russia and her allies were so weak that when we expanded NATO and illegally bombed the shit out of Serbia only the people in former East Europe really got riled, and they had no political power in the West.
Bush the Lesser and Dick Cheney took a giant dump on that situation with the Iraq war. All of sudden having a US passport was not so wonderful. When Bush got reelected I heard a LOT of variations on, "OK, everyone can make a mistake... but electing Bush again?" 2004 marked the globalization of "What the hell is going on in America?"
This is all a prelude to replying to your headscratcher. Obama 2008 was a clear signal from the US populace that real change was wanted. We didn't get it. 2012 Obama still didn't deliver change. Hillary Clinton is one of the worse politicians in history, and as establishment as it gets. Trump was a big, "Did we stutter when we say we wanted change?" to the US political establishment.
Trump is too complex for a simple explanation, but I'll try one. He is not 100% dependable as the steward of US empire abroad, so he must be defeated. That means all the people that refuse to deliver real changes in US domestic policy hate Trump, which (IMO) is his best quality. It is the only reason he stands a chance at winning at all.
No one (IMO) really wants Trump near the White House, but him being in there means that a 100% tools for the US-based MIC like Hillary Clinton, Joe Biden and Kamala Harris are NOT in the oval office making life DEFINITELY worse for the average American.
I hope that helps!