To an ideologue, Lyndon Johnson fits into some category or another. He's despicable, and his crimes cannot be made up for. His lies and his personal reputation make him unforgivable. Alternatively, by passing Civil Rights, maybe Lyndon Johnson is something of a dark hero - a flawed, Batman-like figure who we needed but couldn't appreciate in his time.
The truth is, of course, in between. He's all of these things. The problem lies with us, the categorizers. We want to place him somewhere and move on.