You might be surprised to know what really lights up the phone lines and triggers wide audience participation. Guns? Abortion? Climate change? They all engender interest, but nothing like the response we get when we talk about language and grammar.
Ellen Jovin learned this a few years ago, when she set up her "Grammar Table" for the first time in New York City. People LOVE to talk about grammar, and we get more stories from Jovin's road trips in her book Rebel With a Clause: Tales and Tips from a Roving Grammarian.
You hear more about Jovin's own (widely shared) fascination with grammar and language in this chat on the JX.