You cant ignore the facts about blacks for instance, until 1932, they always voted republican, in 1936 they made an instant, and permanent switch.
In 1932 the black vote being republican, gave the democrats the unsurprising 23%, and in 1936, they made the instant and permanent switch, suddenly going 71% democrat, and staying there.
Yep, they sure did give more votes to the democrats, that is what I said, the fact that it took a few years for party registration to better reflect that instant switch of parties, is meaningless.
Up to 1932, blacks always voted republican, in 1932 FDR got 23% of the black vote, and then the instant switch was made in 1936.
Look at the next chart on the same site:
Notice party identification in the 1940s. It took some time for that to change.
The Jewish vote is the way it is and has been for far longer than a 100 years, because they are liberals.
A little less than 100 years. Harding(1920) scored a plurality of the Jewish vote. Hughes (1916) didn't do so bad either. What we call the "Jewish vote" is made up mostly of Jews whose families came from Eastern Europe. The older German Jewish population leaned Republican in the days of TR and Taft, and Sephardic (Middle Eastern) Jews also come from a different culture with different values.
That's life in these United States, though. Different people have different values. It takes time for them to come to understand things in the same way -- if they ever do. But somehow or other the country has managed to survive and prosper.