Was John Edwards ever considered a "rising star." If so, him. I would also add George Allen, Tim Pawlenty, Sarah Palin, Chris Christie, Bobby Jindal, Patrick Murphey, Scott Brown, John Ossoff, Rubio, and Scott Walker, and there are probably a few others that should be mentioned as well.
People were very high on Edwards after 04 and thought he had a real shot to be president essentially in the "inspiring newcomer" role that Obama ended up playing. Obama is probably the reason his campaign went nowhere.
Palin is a good one too, surprised no one said her. In 09/10 people were talking about her like she was the presumptive Republican front-runner, but then she never held public office again and essentially became a TV pundit, but didn't even get her own show on Fox News or anything.