A Theory for McCain: Nature Abhors a Vacuum

I missed Paul Mirengoff's piece on McCain yesterday. Here's a key quote:

The real question is how McCain is surviving (at least so far) the scrutiny of Republicans in a very conservative state. If McCain couldn't command plurality support from Republicans in Michigan and New Hampshire, how is he commanding it (so far, it appears) in South Carolina. Are Lindsay Graham and company that influential?

Polling is not going to give us an answer to that question but Aristotle had it right when he said "Nature abhors a vacuum". Paul also brought this point indirectly:

Mitt Romney decided that Michigan, not South Carolina, was the place to revive his fortunes. Not only is Romney willing to go after McCain, but he also had the endorsement of South Carolina Senator Jim DeMint. His decision to "go dark" in South Carolina probably helped McCain. Third, Giuliani's decison not to compete in South Carolina means the "moderate" vote won't be split to any meaningful degree. Finally, McCain doesn't need a big number to win the South Carolina primary. He can lose two out of every three ballots cast and still quite possibly come in first.

The Vacuum Theory is that the absence of contestation by a candidate in a multiple candidate field benefits a single candidate disproportionately. Its not that Romney's absence sends his votes to McCain directly. Rather a new equilibrium is sought as the electorate adjusts to that absence. A new candidate is pushed to the top by the reallocation among the remaining candidates via a new subdivision among various groups. Thus with the absence of Romney, the Votes for Huckabee, Thompson, and/or Giuliani reapportion and shift to McCain's favor disproportionately and Romney Votes likewise divide and reallocate with a net benefit to McCain.

To illustrate this better lets assume that there were only two equally appealing (polling at 50% each) candidates. The drop of one, would proportionately benefit the other.

Now imagine 3 equally appealing (polling at 33% each) candidates. Would the dropping of one benefit the remaining 2 such that they would each be at 50%? No. The Vacuum Theory holds that one of the remaining 2 would benefit disproportionately. Unknown, is the individual secondary and tertiary preferences of the voters. Also unknown is larger strategic calculations such as might be represented by perceptions of electability that are not readily manifest or predictable. So it is a logical certainty that one of the two remaining gains disproportionately.

Now make the number of candidates 4 or more and make the divisions uneven at the onset. The permutations grow exponentially. In such a situation it is perhaps impossible to predict who benefits and how they profit from the decline or absence of a single candidate.

It appears also that an artifact of the fractured primary's is that the "perceived" leader benefits from a triangulation among the voters that is not represented had the absent candidate been campaigning more aggressively. It is a strange calculus indeed.

The factor that remains undetermined is what happens with the Undecided vote?