"In multiracial societies, you don't vote in accordance with your economic interests and social interests, you vote in accordance with race and religion."
----Lee Kuan Yew, first PM of Singapore
The wonderment at folk supporting Trump despite obvious ideological differences betrays an attachment to the old, failed paradigm of politics in the USA. The entire world is turning to a new (older) paradigm of ethnonationalism. This is due to the failure of the old paradigm(s) descended from the enlightenment and Marxism.
When the USA was almost entirely not just white N european, but white N european of almost solely English (Saxon, Nordic, Romano-celt from way back) cast, the American Nation could afford ideological repartee and express it in its politics. The fundamental assumptions were all so close that arguing at the margins was pretty much the only argument. The Civil War is the bright line where the old paradigm of a national mercantile republic died and the empire began. Whatever your view of that war and its aftereffects, an honest man can not call a polity where one part warred on and conquered the other part a single nation ruled by consent. Just ask the Irish. (Or the Kurds, the Serbs, Croats, Slovenes, Magyars, etc. etc.)
As the population of the USA became inundated with those not from the American Nation, there were fewer and fewer shared assumptions and politics became more and more important as the arguments were no longer at the margins, but at the core. We (within the confines of the USA) are fast approaching a polity (and politics) that resembles a prison where the whites cluster in the white gang, the blacks in the black gang, and the mexicans in the mexican gang. The fed.gov, its puppet states, and the USA's ruling class play the part of the prison administration.
Truly--blacks, mexicans, and jews have already reached that paradigm and have been working toward the benefit of their own sort for decades. They fight like demons to keep whites from doing likewise, going so far as to make it a thought crime to even contemplate it.
Well, Trump is the American manifestation of the worldwide paradigm-shift toward ethnonationalism. We've seen it manifest itself over the world the last few decades (Yugoslavia, E Europe, Russia's diminished empire, etc.) It is swiftly coming to W Europe and the USA.