The reason is that the USA then was in fact a highly moral, wholesome, and decent society. These are the people that are interested in voting for Trump. That is because they think that will go either in the direction of correcting the fall of the USA into moral depravity, or will stop the fall, or perhaps even reverse it.
My own feelings about this are based on the Talmud. That is a few things stand out when you learn Talmud. One is private property. It is impossible to read any page in the three "bavas" that does not hammer in this point. [Bava Kama Bava Metzia Bava Batra]. The other thing is family values. And simply learning Ketubot of any part of Seder Nashim drives this point in.
I know there are lot so people that are against family values and against private property. That is they whole Democratic party. But I believe that is only because they never learned Torah.
The danger is the Democrats are geared towards getting legal and illegal votes. Thy are galvanized on election day. The reason is nothing matters to them but raw power. Republicans are just not all they much concerned.