Romney is losing ~566 likes per hour. It will take him 886 days to lose them all.
Also here: http://private.woutervdb.com/romney/
and obama: http://private.woutervdb.com/obama/
Also here: http://private.woutervdb.com/romney/
and obama: http://private.woutervdb.com/obama/
Careful, there: http://xkcd.com/605/
The decay looks linear at a glance, but I'd expect it to be exponential on a larger time scale. Time will tell :)
Edit: wanna bet?
Also, Obama's second term doesn't start until January 20, Romney will have been long forgotten by then.
Of course, I didn't like his page, but I'm probably not that atypical. A lot of people use facebook once in a great while and make almost no effort to keep their page up to date, reflective of current friends, etc.