As promised, here’s my initial thoughts on what the Republican field will look like in four years. Obviously, there are many variables along the way, ranging from how beatable Obama looks to the 2010 midterms; I’m just forecasting with the known knowns we have today. As usual there will probably be 10 or so candidates, but from where we sit today there look to be four slots from which to put together a credible primary campaign:

(1) The Populist Candidate: With its Washington leadership beheaded, the GOP is likely to become more of a populist and culturally conservative party in the next four years. Mike Huckabee showed this year the power and the limitations of a pure populist campaign, far exceeding expectations with nearly no resources or name recognition (although Huck was out of step with the populists on one of the major causes of grassroots frustration with DC, immigration). Against the backdrop of a tax-spend-regulate Obama Administration, a crucial challenge will be squaring populism with the GOP’s need to appeal to economic and fiscal conservatives to expand out of the Huck-size niche. Realistically, the populist candidate is likely to end up as the most moderate serious candidate in the field.

As things stand today, Sarah Palin is the obvious populist candidate and, for now, the very-very-early frontrunner for the 2012 nomination, given her now-massive name recognition (the woman’s every TV appearance is a ratings bonanza), amazing talents as a retail politician, appeal to the base, and the GOP tendency towards nominating the next in line. Granted, only two candidates in the part century (Bob Dole and Franklin D. Roosevelt) have won a major party nomination after being the VP nominee for a losing ticket (not counting Mondale, who’d already been VP), those two waited 12 and 20 years before doing so, respectively, and recent history has been unkind to those who tried (Edwards 2008, Lieberman 2004 – see also Quayle 2000).

I’ll expand another day on the challenges facing Gov. Palin – the short answer is that inexperience is the easiest thing in the world to fix, but she’ll have to face tougher budgetary times in Alaska in light of falling oil revenues, she’ll have to withstand what is likely to be an ongoing national campaign by the Democrats to take her down or hobble her re-election efforts to cut off the likeliest threat to Obama, and she’ll have to develop and sell her own, independent agenda and demonstrate a greater breadth and depth of knowledge on national politics than are required from the running mate slot. Upside in the primaries: the socially conservative, moose-hunting hockey mom could potentially be well-suited to the early GOP primary/caucus electorates in Iowa, New Hampshire and Michigan.

(2) The Establishment Candidate: The GOP by tradition tends to fall in behind whoever is the candidate of the establishment – of country clubs and boardrooms and Beltway insiders. Part of being a Republican, of course, is having the maturity to understand that being the establishment candidate is not a bad thing. But an angry grassroots is going to take some serious persuading to pick another establishment figure.

The best establishment candidate should be Jeb Bush, for a variety of reasons, but four years won’t be enough – if any length of time is – to rebuild the Bush brand within the GOP, let alone the general electorate. That leaves Mitt Romney as the logical next step; Mitt is currently out of office and thus less equipped to get more experience, but he’ll have the money and energy to spend four years staking himself out as a consistent conservative voice and putting the distance of time between 2012 and the flip-flop charges of 2008. South Dakota Senator John Thune is also sometimes mentioned, but after 1964, 1996 and now 2008, the GOP has hopefully learned its lesson about nominating legislators for President, especially sitting Senators. Newly re-elected Indiana Governor and former Bush budget director Mitch Daniels (see here and here) will have his name come up but more likely as a VP nominee.

(3) The Full-Spectrum Conservative: The Fred Thompson role from 2008 but one that will pack a lot more potential appeal in 2012. Bobby Jindal is the best of the lot, but while he’s already got an impressive resume, Jindal’s so young (he’s 37, which makes him the age Romney was in 1985), so he can afford to wait out several more election cycles; he’s up for re-election in 2011, which makes running in 2012 very problematic; and he really and genuinely wants to stay in Louisiana long enough to make real changes in his beloved home state’s legendarily corrupt and dysfunctional political culture. The other main contender for this slot is South Carolina’s Governor Mark Sanford, now in his second term as Governor after 3 in Congress. SC is the most favorable turf for a candidate of this type among the early primary states, so with Sanford running as a favorite son he could basically block out any other challengers, and if he doesn’t run for re-election in 2010 (offhand I don’t know whether he’s term-limited), he’d have a logistical advantage over Palin, who will presumably still be in office as governor of a geographically remote state.

(4) The National Security Candidate: After four years of Obama, there’s also likely to be strong sentiment for adult leadership on national security. Traditionally, the GOP has tended to prioritize this issue (in 2008, both McCain and Giuliani ran primarily as national security candidates). But especially with Senators in disfavor, the supply of candidates with more national security credentials than a typical Governor is short – most of the Dick Cheney and Don Rumsfeld types in the party will be past their prime by 2012, and I continue to doubt that Condi Rice could be a viable candidate for a multitude of reasons. The name you’re likely to hear is CENTCOM commander General David Petraeus, but Gen. Petraeus – who I assume will remain on active duty for another year or two, at least, and who President Obama dare not fire – has no political experience and no known domestic-policy profile (we don’t even know if he’s a Republican). My guess is that if we nominate a governor in 2012, Gen. Petraeus will be much in demand as a running mate. After that, I’m not sure who will even try to fill this slot in the primaries.

Sorry, but that’s the list; the no-more-McCains sentiment among the base will make it impossible for someone like Tim Pawlenty to mount a credible campaign as a moderate, nobody will bother trying to re-create the crippling damage inflicted on Rudy Giuliani from running with a record as a social liberal, and no Ron Paul type candidate (especially Ron Paul) is ever going to make a serious dent. It’s those four slots or bust.

And I, for one, am definitely not committing yet to who I’ll support as between Palin or a Sanford or Jindal run or maybe somebody else (obviously I’m not a Mitt fan). There’s two long years ahead of us before that choice begins to arise.