Echoing Smash, the message seemed to be "The reason why people become single issue voters on tpoics such as gun control, immigration, etc is because they don't have faith that either party will help them in issues like the economy". Which I largely agree with. It's not to say that there's anything wrong with being concerned with gun rights or immigration or religion, etc but if you're concerned with them near-exclusively, there's probably a reason why you're more worried about gun rights than who's going to help bring jobs into your state.
However, he said it pretty poorly and should come with a straight apology now and save the nuanced apology for the debates.