I have a bit of a crush, it is true, the man who opposed the death penalty by defending Leopold and Loeb on the grounds that he needed to defend the indefensible in order to make the case properly, the man who defended free speech and reason in Tennessee and humiliated the lawyer on the other side so totally that he died, the man who risked everything to defend union activists in the LA Times case. It is fair comment that Darrow was as racist and sexist and homophobic as most white straight men of his time - but he was one of the people who started changing things.
Dershowitz has something of a point when he mentions that there is something to be said for Jennings Bryan - Bryan had been a great man once, at the time of his 'Will you crucify mankind on a cross of gold?' speech. By the 1920s, he was a pale shadow and had hopelessly drifted into religious intolerance - his denunciations of Social Darwinism are less a sign of humanitarian instinct than the pursuit of any argument on his side.
Darrow was right and Bryan was wrong; it is as simple as that.
Dershowitz argued that the Scopes Monkey Trial was full of grey areas, and really, really, it was not.
One can see though why someone who betrayed his earlier principles to defend torture might want to see Darrow as compromised though...