These pictures were taken 12 years apart. The left was from the 2008 VP debate which can be watch at this link. And the right is from the first presidential debate of 2020, here.

It is astonishing that people seem to think there won't be physical differences between a 67 year old and a 79 year old. Aging obviously isn't a thing so the logical answer is some sort of technology that has no proof of existing. I guess maybe a body double could be involved, but it's a really good body double.