After gauging the harsh reaction from Democrats and Republicans alike to Sen. Zell Miller’s keynote address at the Republican National Convention, the Bush campaign — led by the first lady — backed away Thursday from Miller’s savage attack on Democratic presidential nominee John Kerry, insisting that the estranged Democrat was speaking only for himself.
Basically you can't even see who you're talking to. You are wearing an ear plug and stare at a camera. Mathews was outside in a loud crowd and because it was loud there, he was being very loud when he talked (like we all would be). To Miller, though, it must have seemed like Mathews was screaming at him and worse, because of the background, what Mathews said was probably not coming through clearly. Just loud and angry sounding.
Similarly, Mathews could barely hear what Miller was saying I suspect and kept interupting Miller. The combination would irritate pretty much anyone I suspect let along someone as crochtety as Miller.