The main thing this article teaches me is that middle voters respond significantly to social influences and excitement amongst friends and family. A candidate must build and excite his base; his base will excite and influence voters in the middle. A candidate surely can influence such middle voters as are listening - yet many or most middle voters are not listening to the candidate. They are more socially influenced - possibly by friends whose opinions they respect - than candidate influenced.
James G. Gimpel at NRO:
[T]here is no coherent [political] center. There are no fixed, well-considered policy positions in the center to which voters there adhere.
The research suggests that those who at various times occupy this center, often described as moderates or independents, are not very knowledgeable about or interested in politics. They do not follow campaign coverage closely, are inconsistent in their policy views, and are often not able to identify what positions are liberal or conservative.
What characterizes the centrist voter is not some peculiar set of policy positions, but rather ignorance of policy issues in general, coupled with vague impressions of the “goodness” or “badness” of the times. So-called centrist or moderate voters can’t even be counted on to vote.
Consequently, they make a lousy starting point from which to frame a campaign platform. A campaign doesn’t move toward them, but instead attempts to inspire them to come in the candidate’s direction. The incoherent center moves to the left or to the right, inspired by the candidate’s enthusiasm and the enthusiasm of his supporters. It is foolish for the candidate to move to the center, because the center is never a fixed position to move toward.
Moving centrists toward one’s candidacy is not a process that hinges on taking the right policy stands, either. Instead, it involves the enthusiasm and social contagion that builds around exciting candidates. We know from several volumes of political-science research that less-informed voters commonly substitute someone else’s judgment for their own. That someone else is often a spouse, workmate, or neighbor knowledgeable and enthusiastic about one of the candidates. Support for a candidate spreads through social influence processes.
It is therefore no accident that Sarah Palin’s nomination gave John McCain the only lead that he had during the fall campaign. She was Senator McCain's only hope for closing the enthusiasm gap, but then economic crisis stalled the gains. Polls will show that Barack Obama had social contagion working in his favor to pull the incoherent center in a leftward direction.
A candidate with Sarah Palin’s views is not the only way to generate enthusiasm and move the incoherent center. But the path to victory is to find a candidate who will pull the center in their direction, not to modify policy stances in hopes of making inattentive and ambivalent voters pay heed.