Except he didn't just have a raspy voice. He was mixing up words, rambling, even struggling to put full sentences together at points. And when he wasn't talking he looked to be spacing out at times, just trying to hold it together at others. His performance was as if he was fighting a very high fever, a migraine, and/or was trying not to puke the entire debate. I totally believe reports that he had a minor illness and was having an off day as a result, but unless he had something like the flu (in which case he wouldn't have been allowed on stage, certainly not that close to Trump) it would be completely reasonable to expect him to perform much better even while sick.

I think that matters to voters, because as president you don't get to take a sick day; shit goes down and you need to be there for it. Maybe he's not too old to be president on days when he's feeling well, but I think a lot of viewers last night thought he looked completely incapable of handling any kind of sudden crisis in his condition last night.

Obligatory: assuming he's still the nominee I'm voting for Biden in November anyway because all the alternatives suck more.