There has been some recent rumbling — added to today by Chuck Todd — that a credible centrist 3rd party candidate for the Presidency might emerge next Spring. And by the way people are talking, they don’t mean “John Anderson credible,” and they don’t mean “Ross Perot credible.” They mean the real deal: Teddy-Roosevelt-Bull Moose-1912-win-more-electoral-votes-than-one-of-the-major-parties credible. Someone who would have the background to not only qualify in voters’ minds as a legitimate candidate, but also actually be a threat to win the Presidency.

Of course, the mere possibility of this  is predicated on the following three conditions holding true: first, President Obama remaining relatively vulnerable (probably because the economy continues to stagnate or get worse) due to unpopularity among self-described independents; second, the Republican nomination process producing a candidate far enough to the right that a significant number of said independents might still prefer Obama to the Republican nominee, ex ante; and finally, the existence of a plausibly-electable candidate that would have the desire and resources to become a  major player from the center.

In this post, I’d like to consider some of the  institutional constraints that might influence whether or not a credible centrist third party candidacy develop, and put some historical context on the issue. Seven points:

1) How conservative a nominee would the GOP have to nominate to provide the space necessary for a centrist 3rd candidate? Contrary to Chuck Todd, I think probably more conservative than either Perry or Romney. There’s not a lot of evidence right now that Perry is conservative enough or enmeshed enough in the Tea Party to generate the space needed for a centrist challenge. If you take a look at this ideological map of the current candidates, a few things stand out. First, there’s not that much room right now between Perry and Romney, despite all the talk about Romney appealing the moderates and Perry appealing to orthodox conservatives. What is happening is that — as a Downsian model might predict — two ideologically similar candidates are appealing to different portions of the party. So contrary to some conventional wisdom, it’s not obvious that, in a general election, Romney would ideologically appealing to centrists and Perry unpalatable to them.  Furthermore, it’s not clear that Perry would make a bad general election candidate, once the field is cleared and he can safely tack toward the center.

Bachmann, I think, is a different story. Not only is she somewhat more conservative (based on the Poole/Rosenthal method from the linked map), but she is fundamentally and irrevocably associated with the Tea Party, which would be a major selling point of a centrist 3rd party candidate. So I think the chances of a 3rd party candidate were much higher prior to Perry’s entry into the race, when Bachmann had a much greater chance of winning the nomination. If Romney wins the nomination, there will be no 3rd centrist challenge, period. And while I wouldn’t rule out a credible 3rd party challenge in an Obama-Perry race, I think the chances are pretty low, barring some contingent event that dramatically changes the calculus.

2) The nomination system and campaign laws are going to severely limit where the challenge would come from. The campaign finance laws enacted in the early 1970s make it more difficult, on balance, to enter the race late. Fundraising needs to begin early, and so does campaign organization. Consider 1968: Senator Kennedy joined the race on March 16, after McCarthy’s excellent showing against LBJ in the New Hampshire primary. It’s hard to imagine that a 3rd party challenger could start from scratch that late in the current environment. Money cannot be raised fast enough at the current maximum donation levels. Campaigns have also become, in real dollars, more expensive. And such a candidate would be without the help of a major party to organize and support the campaign (unlike Kennedy, had he won the nomination). Which means any centrist challenger would likely need to have one of the following two attributes: enormous private wealth (i.e. Perot 1992), or an existing campaign infrastructure from having already been in the campaign for the GOP nomination (i.e. Anderson 1980).

3) Are there plausibly centrist candidates that have the desire/resources/ideology to do this? The two most-talked about plausible centrists are Huntsman and Romney. Both are already raising money for the primary, and both have significant personal wealth that they could plausible draw upon. Huntsman is an honest-to-god GOP moderate, and Romney wouldn’t have a lot of trouble fitting that bill either, once he was unshackled from the need to court GOP primary votes.   Bloomberg is often mentioned, and he’s got the personal wealth and plausibly the ideology, but probably not the desire. Others who are not currently in the race can probably be written off: Christie is not an un-wealthly person by any means, but has nowhere near money to fund a campaign. Ditto with Daniels, who probably is too conservative, anyway. I presume McCain is too old, too exhausted, and now too tied to the party orthodoxy  to make a go of it. And, just for kicks, remember that the Governator is constitutionally ineligible.

4) Would someone like Romney or Huntsman be willing to fracture the party by putting up a candidacy? I don’t see why not. Huntsman has already worked in the Obama administrations, so his partisan allegiance can’t be total. Romney certainly has a long family history with the party, but his personal allegiance to it is unknown. Circumstantially, you can imagine he has the necessary prerequisites to jump ship. He’s a business-first conservative and a member of religious minority in a party that is increasingly drifting toward the social conservatives and becoming more enthused with a religious base that is at least partially skeptical of Mormonism. It wouldn’t be hard to write the speech he would give upon leaving the party.

5) Where would a Vice Presidential candidate come from?A lot of the talk you hear centers around the idea of a unity ticket — someone like Huntsman or Romney pairing themselves with a conservative Democrat who’s not particularly attached to the party, for the purposes of transcending partisan affiliation completely. Someone like Senator Webb.  While that’s plausible, I think it would just as likely that the pick would come from the right half of the middle. Romney might very will go with Huntsman. Another possibility would be to grab someone more conservative, but still wonkish and plausibly a cross-the-aisle kind of guy. Like Portman. But the bottom line is that it could be anyone; unlike the top of the ticket, existing money or infrastructure resources would be a plus, but not a prerequisite.

6) Could a Romney-Huntsman or Romney-Webb ticket win? I think it’s plausible. The strategic voting possibilities would be fascinating, since virtually every voter would list Romney-Webb as at least their second choice. Remember, there was no opinion polling in 1912 or 1860. Voters had little ability to coordinate. In a serious three-way race in 2012, voters in states where their candidate was obviously going to come in 3rd would have strong incentives to switch their vote to Romeny-Webb, since it would clearly be better for them than allowing the opposite-party candidate from winning. If nothing else, it would be fascinating to observe.

7) Would such a candidacy result in a durable 3rd party? Doubtful. The iron logic of the majority-vote single district system is that it inevitably leads to a two-party structure. Even more so, a third party would not be fielding lower-level candidates, and perhaps not even see itself a creating something durable. A Romney-Huntsman ticket might actually be claiming that it was the “true” Republican party. In any event, don’t expect such a challenge to have a lasting effect — as with Roosevelt, it would be an attempt to shift an existing party onto a different track, not create something new for long-term competition.