Ramesh Ponnuru wants to know why I think McCain-Huckabee is “obvious”; commenters on my predictions post want to know why I think the same of Obama-Webb. So: here’s why.

First, I admit, “obvious” left open whether I meant, “obviously the right thing to do” or “obviously the thing he’s going to do” – and that was deliberate, because I kind of meant the combination of both; that is to say, I think they each will pick these men for VP, in large part because these choices make sense for and to them.

And I didn’t mean to suggest that Huckabee would not make sense for any of the other candidates. I think he would make sense for Giuliani. I can’t see any possible reconciliation or chemistry with Romney, so it’s not a plausible pick, and I also question whether Romney, having run as a values candidate, wants to pick another values candidate as his running mate; a “Mormon-Evangelical Unity Ticket” does not add up to a majority. And I fully expect, if Romney’s the nominee, to pivot, as he has all through the campaign, to the place he thinks he needs to be to win. Which means he’ll pick an acceptable moderate – hence my Kay Bailey Hutchison prediction. The point is: I was making an argument about McCain, not about Huckabee.

So: McCain. I believe, at this point, that the GOP is willing to tolerate him as the nominee, but they don’t love him. More to the point, no part of the party loves him – the Club for Growth types can’t forgive his apostasy on the Bush tax cuts or his support for Kyoto; the social right can’t forgive the whole “agents of intolerance” business; and even the national-security right is suspicious of his desire to shut down Guantanamo and end the practice of torture by American military and intelligence personnel; and then there’s campaign finance reform and immigration, which cut across the traditional three “legs” of the GOP coalition.

Huckabee bolsters McCain’s support with the group most important to winning the general election and the group with whom McCain has, objectively, the fewest disagreements: the social right. Once he has won the nomination, the economic right has nowhere else to go, and the national security right can’t possibly prefer the Democratic candidate to McCain, whatever their hesitations about him as the nominee. And McCain genuinely believes the stuff about ending torture, matching tax cuts with spending cuts, and combatting global warming, so picking a candidate who was on another page on this stuff would be an obvious shotgun marriage. By contrast, McCain has no real substantive disputes with the social right – he’s just not actually part of the bloc of the faithful, and managed to alienate them profoundly last time around. So picking Huckabee would make a difference in winning more of these people back to his camp.

And he needs these people. Downscale values voters could plausibly stay home in 2008 if they don’t think they have a nominee who they have reason to support. Particularly if Hillary Clinton is not the nominee, it will be hard to bring them to the polls with a purely negative message. Huckabee, for a while there, really spoke to these voters – and may still; we’ll see soon enough. In any event, even if McCain is “fine” with this group of voters, who else does he need to win over more? He already polls very well with independents; he doesn’t need to pick a “moderate.” And he certainly doesn’t need to pick someone with particular expertise. If “fine” is not enough, Huckabee helps.

Moreover, he likes Huckabee, and Huckabee likes him. A good working relationship with one’s VP is generally a good thing, on the campaign and in the White House.

Now, there’s also a downside. Huckabee is plainly not ready for prime time. I personally don’t he has the makings of a President, and whoever McCain, if he’s the nominee, picks as VP will have a leg up to succeed him should he be elected. I’m not sure Huckabee is the right person to be Vice President, but that doesn’t mean he’s the wrong person to pick. Most important from a political perspective, Huckabee may make himself toxic by flaming out spectacularly on the campaign trail. But again, we’ll see. If Huckabee loses the nomination, dropping out after losing South Carolina or Florida but having made a decent show, and retains the affection of his particular slice of the voting public, I think he’d be a very solid pick for McCain, and one that McCain himself would be inclined towards.

Now: Obama. Obama does not need someone with a lot of legislative or executive experience on the ticket. He does not need a gray beard or someone who will overshadow him. The fact that Webb is a first-term Senator is not a liability.

What Obama needs to do is reassure people who are nervous about voting for a black man, nervous about voting for a Harvard man, nervous about voting for a man who grew up in Hawaii and came up in politics from Chicago’s South Side.

Moreover, Obama – who has run his primary campaign as if he intends to draw a contrast on foreign policy in the general election – needs to reassure voters that he is ready to be Commander in Chief. He’s had no relevant experience whatsoever in that particular area.

Webb covers both bases, without overshadowing the nominee. Webb is a guy who wrote a book about his pride in his Scots-Irish heritage. He campaigned – and won – in Virginia on a platform of economic populism and protectionism (whereas Obama is a free-trader who seems basically comfortable with the globalist consensus on economic matters). Webb would substantially respond to any antipathy by certain voters to voting for a man who could simultaneously represent the lumpen and the uber of our social order.

Moreover, Webb is a former Reagan Secretary of the Navy who left the GOP for two reasons: because he thinks the GOP’s economic policy is detrimental to working people, and because he was disgusted by the Iraq War. He has far more credibility as a spokesman for a change in foreign policy than a John Kerry or even a Wesley Clark. Inasmuch as he and Obama see eye-to-eye – and they don’t, precisely, though I think they do more than they don’t; Webb, as a former Navy man, is no Buchananite neo-isolationist – Webb’s presence on the ticket substantially bolster’s Obama’s critique of the direction of our foreign policy. This becomes especially important if he’s up against McCain, but it would also be extremely useful against Romney or Giuliani.

Again, there’s a downside. Webb is a basically lousy campaigner. He doesn’t play well with others. I don’t know whether he could tolerate being Vice President, playing second-fiddle for four to eight years, or even for a whole campaign. But I don’t think he’d take the job if he didn’t think he could do it. And he grew up some as a campaigner over the course of 2006.

In any event, regardless of whether I overstated by calling these picks “blindingly obvious” – who’s an obviously better pick? Would Tim Pawlenty, Lindsey Graham, Joe Lieberman or Fred or Tommy Thompson be an obviously better pick for McCain? Would any of them help him with a key constituency or demographic more than Huckabee, or create a more striking positive press response? And would Evan Bayh, Wesley Clark, Bill Richardson, Joe Biden or Tom Vilsack be an obviously better choice for Obama? Would any of them make the nominee look better in the eyes of key demographics, or be a powerful campaigner for the ticket, or generate any excitement at all?

I notice there’s something in common to my two VP choices: both choices are predicated on the notion that the white working- and lower-middle-class will be a key demographic battleground in 2008. These are the people who have shouldered a disproportionate burden of our current foreign policy, who have benefited less from the economic growth since 2002 than wealthier demographics (I don’t know how things hash out between white- and non-white working class folks in terms of benefiting from the last five years), and who are the most concerned about the cultural direction of our country and the unraveling of the American family. Huckabee and Webb would both be picks designed (in part) to help the ticket compete better for these voters. That’s not the only thing they’d each do for their tickets, but it’s an important element. If I’m wrong about that key element – or if I’m wrong that McCain and Obama, in different ways, could use help pitching to this demographic – then I may be wrong about the obviousness of their VP picks.