Because hatred and fear are powerful motivators for stupid people.
Oh, and by the way people don't keep choosing them over the democrats. Democrats have won the popular vote in 6 out of the last 7 consecutive presidential elections.
Nope, other way around. Republicans are the cultists(although not satanic) who wish to destroy this nation. They make up the vast majority of the Republican voting block. But for 50 years the Republican establishment has been able to maintain control over them, and put forth a shinny enough face come election time to do okay.
The election of Donald Trump has proven beyond a shadow of a doubt that every single solitary thing liberals have been saying about Republicans for over three decades is absolutely 100% correct. They are a party made up largely of racist, misogynist, homophobic, xenophobic, gun toting, religious nut jobs. Aka, the dumbest, and most hateful mother****ers on the planet. This rabid base of morons is kept in check by an establishment of Wealthy business people who give a little wink and a nod at them come election time, and put on a smiling face for the rest of the country.
It all started with Richard Nixon. He looked around the country and realized there was no way in hell any sane rational middle class or lower income voters would ever vote for the economic policies of the Republican party which are designed exclusively to help those who are already wealthy. So he came up with the Southern Strategy. An attempt to court non-sane and non-rational southern whites who were foaming at the mouth over the civil rights movement. He knew these people were stupid enough, and racist enough to vote for him regardless of how bad his economic polices were for them. All he had to do was slyly hate on blacks, hate on foreigners, tout Christianity, and tell them liberals wanted to take their guns away.
Everything was working perfectly until their shinny elitist candidates lost two consecutive presidential elections to a black man. All of a sudden the crazies got fed up. They realize their hateful garbage is on the way out, and they decided if they were going to go down, they wanted to go down with a candidate that truly represented their hatred and bigotry.
Unfortunately desperation over a supreme court seat by moderate Republicans, and a liberal voting block who just assumed there was no way in hell Trump could possibly win allowed them to get away with it. So now we're all ****ed.
