Erica Grieder makes a good point:

Incidentally, I’d like to register an objection to the recurring suggestion that Mr Daniels, Mr Christie, Mr Bush, etc, could have won if they had just run. Pretty easy not to lose if you don’t try, isn’t it?

I agree. I refer to these politicians collectively as fantasy candidates in part because I assume that it is a convenient fantasy to believe that one or all of them would have been very competitive and appealing to the GOP primary electorate. If the Republican field seems unusually weak, that is because so many people have sustained the illusion that the “strongest” candidates aren’t running, when it is just as likely that none of them is running because each realized in turn that he wasn’t going to be able to compete with Romney. Indeed, some of the “strongest” candidates were so strong that they briefly entertained the idea of running before ruling it out as undesirable or impractical, which suggests that what some people mean by a “strong” candidate is one that they happen to prefer rather than one who would be competitive. One problem is that many of the same people who were urging these politicians to run have been invested in building them up as heroes of the party. No doubt these enthusiasts really wanted them to run, but it’s also likely that they confused their enthusiasm for them with the way voters nationwide would actually respond to them.

It’s possible that some journalists have built up the fantasy candidates as “strong” contenders because they would find the race more interesting to cover with them in it. For example, scratch a journalist who claims that Chris Christie would be a formidable presidential candidate, and I suspect you’ll find a journalist who is intrigued at the possibility of reporting on what could prove to be a political disaster in the making. Meanwhile, some conservative pundits may have kept the fantasy candidate idea alive for so long as a way to maintain interest in a contest whose ultimate outcome was never really in doubt. Speculation about the fantasy candidates was amusing and harmless as far as it went, but it was mostly based on wishful thinking and nothing more.