Chris Christie is out of WH 2012. You'll see lots of people saying he decided not to run. You know what? I think that's probably wrong. I think he did run for president for a few weeks, and has now been winnowed out. Chalk another one up for the invisible primary.
Now, as campaigns go, it wasn't much; it's not like the full-fledged Tim Pawlenty campaign, or even the mostly-fledged Haley Barbour effort. But by all accounts (including his own, really) he looked around to gauge his support, and he certainly delivered at least one campaign-type speech at the Reagan library last week, and that to me is a campaign.
How should be understand the rise and failure of Chris Christie? One way is factional: there was, as Josh Marshall theorizes, a party faction that supported his candidacy. I think that's probably accurate, and what Christie's demise tells us is that he rapidly discovered when he looked around that (1) it's a relatively small group within the party, and (2) most other party actors are reasonably happy with either Rick Perry or Mitt Romney or at least the choice between them. Or perhaps he heard that his record of moderation made him an absolute non-starter for important party groups (such as, say, the NRA). To put it another way...Marshall says that Christie is making a "smart move" because "a pro-civil union, global warming believing, sharia-loving, non-Mexican hating New Jersey governor just ain't gonna survive first contact with the GOP nominating process" -- which I'd reply that we may well have just seen him not survive that first contact, and what he was smart about was doing it more or less out of the limelight.
That said, I've talked before about the possibility that interest in running is probably more than an on/off variable. In other words, perhaps Christie was interested in running -- but not desperate to do so. In that case, it may have only taken relatively light resistance (and the promise of a hard race) to dissuade him from continuing on to a formal declaration of candidacy. What we don't know, from the outside, is exactly what perceived odds of winning Christie would have needed to proceed. Hey -- it's even entirely possible that he couldn't tell you accurately exactly why he chose not to continue. What we can say, no question about it, is that the GOP seems to be highly efficient at winnowing the field, and this is yet another piece of evidence for that.