When there were still two Primary races, Romney was accused several times of lacking a principled core – something which voters could point to and know that it would determine his views on policies or specific situations he would encounter as president. His pragmatic approach – gathering lots of smart people and a truckload of data and working things through to their logical conclusion – was said to be less than inspiring.

The irony, as I’ve come to realize in the last few days, is that Obama also lacks a principled core – but in his case it’s the very fact that he’s focusing on being inspiring that is masking this fact. Yes, he has a set of buzzwords which are the spine of his campaign – but they’re not about principles – they’re about abstract nouns: “change”, “hope”, “belief” etc. These are inspiring words indeed, but they tell us absolutely nothing about what moral, ethical or rational framework Obama would use to inform his policy decisions as president.

Romney at least had a set of specific proposals and policy positions that people knew about and could weigh up. Those positions also signaled how he would approach other, related issues. But Obama doesn’t have any policy positions either. All he has are those empty words that lift the spirit but provide no guidance on how he would make decisions. And because he’s also relatively unknown as a personality, too, he doesn’t even have that to fall back on. Other than his tendency to speak in lofty terms and to claim (though not actually to follow through on the claim) that he is above the usual political tactics, there’s nothing to define Obama the man either.

The comparison with Romney is an interesting one, but it’s not all that relevant at this point. What’s more relevant is to compare him with the other remaining candidates, and also to think about the implications if he does become president. McCain perhaps lacks an obvious principled core, too, but the force of his personality and his long service in the Senate give some pretty powerful pointers to how he would act as president. Hillary Clinton has less experience as a Senator, but has nonetheless been in the public eye for a long time and has a publicly perceived personality, and has also been much more specific about policy proposals than Obama. Both come off more favorably than Obama if you look at this particular issue (which not everyone is – so far the lack of substance hasn’t cost him too much).

What does this mean for an Obama presidency? Well, Newt Gingrich has some interesting thoughts in the “letter” to Obama he wrote for Newsweek this week:

The challenge you will face in the next few months is stark. Do you want to remain vague? You might win—but you might find that, in winning, you have a “victory of personality” with no real policy consequences. Or do you want to provide specifics? If so, your victory could be a clarion call from the American people to Congress to join you in achieving your goals.

A downfall of this approach is that people have little to measure Obama against other than idealism (which is always going to be an impossible bar to measure up to), and little to vote for next time except the personality (which will inevitably have been tarnished by four years in the White House). It’s in his own long-term interest to provide more than just his airy rhetoric, even though it might appear in his short-term interest to stick to it and so avoid losing support by being specific enough to offend some people.