Complex sentence: According to Gabler there was no evidence that he expressed any hatred or bigotry against any racial group, but he would occasionally make racially insensitive remarks that were commonly used by white Americans at the time.
Split into simpler sentences: According to Gabler, he was not, never expressing any hatred or bigotry against any racial group. However he would occasionally make racially insensitive remarks that were commonly used by white Americans at the time.