You‘re able to see no relation between Hitler and Trump because you don’t want to. You said “Hitler accused the Jews of all kinds of things and others.” What has Trump done to people of color (“Chicago is a warzone”?) and to immigrants who many in this country rely on (look at what’s happening to farming in Alabama, and how they don’t have people who can do the work).
As for the how, it’s happening with the GOP — they know Trump isn’t fit for the job of president, but they prop him up and make excuses for him, so they can execute their agenda. You can blame the “libtard” “snowflake” “sheeple” all you want, but I’m going to look at what the man says and what the man does, and judge him on that. He’s bent on autocracy (his reaction to media is pouty and “SAD” — remember some Obama coverage when you get a chance); and injuring the people of America (from removing instead of improving healthcare; killing base regulations from clean water act; not tracking what goes into pet food).
I’ve tried to find an argument for Trump, and there isn’t one. You can support the GOP because you believe in a conservative society (which Gorsuch will work to enact for the next 40 years), but you can’t deny their obstructionism during the Obama era (though maybe that’s good politics?) and their White Supremacist agenda (Jeff Sessions re-enacting jail time standards proven to not work; bolstering private prisons as they pour money into Republican bank accounts — one spent $250,000 on Trump’s inauguration party) and their consistent use of mistruths to move forward policy (current health care bill).