Well it’s quite evident why Patton would want to fight for the Nazis based on his views

“So far as the Jews are concerned, they do not want to be placed in comfortable buildings. They actually prefer to live as many to a room as possible. They have no conception of sanitation, hygiene or decency and are, as you know, the same sub-human types that we saw in the internment camps."

The letter also refers to the people of the Soviet Union as “the degenerate descendants of Genghis Khan” and says the envy, hatred, malice, and uncharitableness in Europe “passes beyond belief.”

As Cato the Elder would’ve said,

Washington D.C. delenda est