First, understand that the manifesto the terrorist posted is filled with nonsense intentionally designed to distract and stir controversy. This helpfully weeds out a lot of the distracting nonsense designed to stir people up based on the darker recesses of the internet.
Second, once the garbage is weeded out, read this piece that looks at his claims.
The terrorist liked Donald Trump to the extent Trump used populism to stir up white voters, but hates Trump policy wise. He is sympathetic to the ideals espoused by Bernie Sanders and wants state control of corporations.
He thinks corporatism and individuality are bad things and hopes for a civil war in the United States to preserve the white race.
It is all deeply disturbing and very demented.