Pence can take the risk of catching the virus if he wants to, but he doesn't know he hasn't already got it, and so he should wear a mask in such a place to minimise how much he might spread it if he has it. It's courtesy, life and death style.
I had to go to the doc's the other day, and that's the only time I've worn a mask. They were only letting people into the building one at a time. I put a scarf on my face. I've been so isolated, I'm pretty sure I'm not carrying it, but the docs don't know that so it was an attempt to reassure them really.
