First the obvious disclaimer. Maher was there to hawk a book, and not give any indication of changing ideological teams.  Quite a price to land him for the show.  GG allowed him an entire block to allow him to discuss.  Still,  this is the biggest high profile guest he's landed. 

I think the intent was showing that there is a lot of agreement, if we forego and tone down the rhetoric.  Show did try to focus on agreeing, rather than red meat that Gutfeld throws to the crowd.  Common ground. seemed the theme.

Mahner did go into his Trump insurrectionist rant. He also made a point that it was important to differentiate Liberalism and "Woke".  He seems to think that the two really need to be decoupled.     

Over all, minimal friction.   And I for one, have always thought that Maher was 75% reasonable, and a TV political pundit that is a rare rational Liberal.  Disagree with him 95% of the time,  still, he often provides an interesting take to the counter POV.