The point is EVERYONE considered this Bush bashing Trump. Its not just Trump supporters interpreting his comments in the context of their own guilt, as you imply.
If everyone said the earth was flat, does it make it so? And no, not everyone is as I pointed out.
And if you take off the Trump blinders and read the actual speech without it, he makes a very good point.
Instead of assuming when he talks about racism and division he is talking about Trump, maybe read it as he is talking about the rise of people like Richard Spencer, BLM, Antifa, etc. How is he wrong?