The main reason Trump was elected was because grassroots America got tired of being ridiculed for their traditional beliefs.
The Obama administration moved this country further left in an 8-year period than had ever happened before. He fought the NRA, sided with criminals over police, and lit up the White House in LGBT colors. Then ridiculed anyone who disagreed with these things.
I think the LGBT coloring of the White House was particularly over the top. It was a victory dance and spiking of the football by Obama. He didn't have to do that, but he did. He chose to. He just had to rub it in. And IMHO, that along with other Obama slights against conservatives galvanized them against the democratic party.
Then, the best the democrats could do was Hillary? Hell, my dog could have run against her and won. This is how bad she was/is: she couldn't even beat Donald Trump. Enough said.