The uneven roundtable discussions of Larry Wilmore’s new The Nightly Show on Comedy Central demonstrate just how hard it is to handle a coherent, much less entertaining, TV conversation among several volatile guests – yet Bill Maher has proven impressively adept at it, week in and week out. And on weeks such as this one, where there’s no superstar big name to dominate the proceedings, both Maher and his panel tend to be at their very best.