It is true, as various conservatives have pointed out, that Democrats cannot exactly attack Palin for her inexperience, per se, when they have Barack Obama at the top of the ticket. The Dems can't "go on offense" with regard to the experience issue.
It is also true, however, as various liberals have pointed out, that Republicans will now have a harder time explicitly advancing the "inexperience" argument against Obama. The NRO argument -- "if you think experience is important, would you rather have it as at the top of the ticket or at the bottom?" -- only goes so far.
Bluntly, John McCain is old. He might die. If you're going to hang your hat on the "Ready To Lead" mantra, as essentially the central organizing principle of your candidacy, and then you pick a veep who is quite clearly not "Ready To Lead" by the standard you've set, it is not a particularly convincing defense to say, "But she's only running for vice president." Vice presidents can become president, sometimes quickly. Voters instinctively understand this, particularly when the presidential candidate is the 72-year-old cancer/torture survivor McCain (to whom, incidentally, Happy Birthday!).
Thus, although the Dems can't use the "inexperience" card offensively against Palin, they can use it defensively, to shield Obama from further direct attacks on this front. Anytime McCain says Obama isn't ready to lead, and uses his slim resumé to support this point, Palin will be the obvious rebuttal.
This rebuttal will pose a serious problem for McCain, message-wise. Some folks are suggesting that Palin's "executive experience" as a small-town mayor and a half-term, small-state governor is some sort of trump card. But that's implausible on its face. As for the notion that "but, but, she's only the veep" -- this is an inherently defensive argument. It's nitpicky. It doesn't sound good. It's bad for the "narrative."
As Andrew writes, "Sure, the GOP can find ways to excuse Palin's inexperience, trump up her experience, and continue to attack Obama on the basis that he's a presidential candidate with limited experience whereas Palin is just the VP candidate, but that message has to be too nuanced and contextual to be effective. The voters need simple messages that resonate, not complicated ones that must be digested and contemplated."
To be clear, the thrust of the Dems' argument will not be that Palin is too inexperienced; it will be that McCain is being disingenuous when he argues that Obama is too inexperienced. This argument will gain wide acceptance among the pundit class, and it will also succeed with voters -- largely because it is correct, and obviously & instinctively so.
McCain will not be able to spin the contradiction away. I think he's smart enough to know this, and will not try.
In short, I think McCain just knowingly, willingly surrendered the ability to continue directly, explicitly using Obama's inexperience as the line of attack at the heart of his campaign. Why?
I think McCain has concluded that he has already successfully framed Obama as being too inexperienced to be president, and that this framing is already so cemented in the minds of voters that McCain no longer needs to explicitly make the argument. He only needs to tacitly allude to it, in ways sufficiently indirect that Obama won't be able to pin him down and point out the contradiction, and the media won't call him on it (much like his patriotism double-talk).
Furthermore, I think McCain believes that voters who have accepted and internalized the "Obama is too inexperienced" meme, will not be bothered by the cognitive dissonance inherent in: 1) continuing to believe this, while 2) being unbothered by Palin as veep. Part of the reasoning here is that because nobody will be directly attacking Palin's inexperience (see "Dems can't use it offensively," above), the inconsistency won't really occur to many voters, especially low-information voters. And if it does, they won't think about it too hard. (If they thought about it too hard, the age problem I mentioned earlier will come into play.)
Is McCain right in these conclusions that I believe he has reached? I don't know. Nobody can know. This is why I titled this post "the Palin gamble." McCain is gambling that he -- with a huge assist from Hillary Clinton, circa March, April and May -- has already successfully defined Obama as "too inexperienced" and "unready to lead," and that Obama, having just finished his convention, has failed to re-define himself so as to shed or at least weaken this label. McCain thinks he's won this argument, and so can now afford to stop making it. Whether he's correct in that assessment may determine who wins in November.
Or, I may be completely wrong, and McCain will just plow ahead with his "Ready To Lead" messaging in spite of the inherent contradiction, believing that voters will truly make a total and complete distinction between the top of the ticket (experience is the be-all, end-all) and the bottom of the ticket (experience does not matter at all). But I don't think so, because I think McCain & co. would look disingenuous and parsing and defensive if they have to try and make this distinction, and I think they know it. The punditry certainly would not buy the argument, and I don't think voters ultimately would, either. Again, I think the McCain braintrust is smart enough to know this.
Anyway, game on.
P.S. With regard to the idea that Palin has "more experience" than Obama, one important fact to consider: Palin hasn't been running for national office for 18 months. Obama has. Running a presidential campaign is a form of "executive experience." At the very least, I'd say reasonable people can disagree about which type of experience is more relevant to serving (or potentially serving) as president: being mayor of a tiny town and governor of a tiny state (population-wise), or being "chief executive" of what has been, by most accounts, a massive and pretty damn well-run national organization that has successfully dethroned the Clinton Machine and remade the Democratic Party in its image.
I'm not insisting on a particular answer to that question, but certainly, the "experience" analysis must include Obama's experience running his campaign. It is no small matter.