No reasonable person supports extremist groups.

The only group mentioned in any of this I personally support is the ACLU, which defended the right of the white supremacist groups to organize. This did not change my support for them. 

Extremist groups have the right to organize, and rallying in counter protests does not equate your messaging to theirs. That is the problem. Trump seems to think that because there was a counter protest to hate and bigotry then both sides are equally hateful and bigoted. It's objectively not the case. 

This "there are problems on the left too" to any criticism of Trump and the alt-right are getting extremely tired. Being critical of one extreme does not make you complicit in the other. Yes, we should condemn extremism of both sides, but in this specific case the only official group that organized was the extreme right and they should be condemned for their bigotry, hate, and violence. They do not deserve sympathy, and they were not "nice people".