Original sentence: Since Gamergate, he has covered topics such as identity politics, the alt-right, Brexit and political correctness
Edited sentence: He stresses the importance of free speech and viewpoint diversity in improving societal cohesion in a liberal society, and has not been afraid to debate controversial figures in the culture war, including  members of the alt-right.Since Gamergate, he has covered topics such as identity politics, political correctness, and their contribution to the rise of political extremism