I've recently found quite the white whale by way of this video:
The primary sources used all appear to be of people impersonating Barack Obama to some degree of quality, all with Earth Wind and Fire's September in the background. The date this video was uploaded suggests that it came about around the time of the 2008 election. I've done quite a bit of research, but so far I've come up short. Definitely going to need some help to figure this out.
I should note that the uploader said in the comments that the main sources were provided by someone they knew at the time, but none of those sources were available on Youtube.
Nobody Is As Ready For Pillowy Mounds Of Mashed Potatoes As Uncle Phil