I'm not sure I'd go with McCaskill or Reid, seeing as they both, especially Reid, manipulated the republican primaries to get the candidate they wanted. So it was more skill than luck. Chris Coons wouldn't be a bad choice.
Yeah, this is the correct answer. Coons went from the status of complete nobody to that of future US Senator by virtue of events no rational mind could have foreseen.
I'm sure... If Coons ran against Castle in 2006, 2008 or even 2012, given how blue Delaware has become, I'd probably bet on Coons winning, (Which is probably why Castle didn't run in any of those years)
You mean apart from the fact these elections were contested by extremely popular incumbents, as opposed to some random dude?
Delaware is one of the few States left where retail politics and personal appeal can still weigh more strongly on voter's choices than partisan gravity, at least if the candidate is already an established officeholder with a centrist and uncontroversial record. After all, if Castle was able to retain his House seat amid the 2006 and 2008 democratic waves, it's not too hard to envision him winning a Senatorial race against Coons if Carper/Biden somehow hadn't run.