You believe correctly. It is a vicious hit piece, all done with inapt innuendo. LBJ was the opposite of Donald Trump. He was, if anything relevant to the present, a male Hillary Clinton. He did violate election laws. He did push through a radical change to our immigration laws, one favoring inconguous immigration--which has actually been subsidized;--as well as increased Federal meddling in local education & health care.
If you are a student of the art of the smear, you will recognize many tactics used by the writer. This is one more example of how far National Review has fallen from its own standards in the 1950s. This is contemptible trash.