Enthusiasm Gap? What about the Loyalty Gap?

There seems to be a lot of talk here and elsewhere about the "enthusiasm gap" between McCain and Obama. We know that Obama's supporters are far more enthusiastic about him than McCain supporters. This is supposed to be a big boon to Obama.

I don't see why. After all, if you cast an unenthusiastic vote, that counts as one vote. I you cast an enthusiastic vote that too counts as one vote. Oh, I know that grassroots campaign activities can be affective in the campaign. But you don't neccessarily need massive enthusiasm to do that.

I think the real story everone's missing is the Loyalty Gap, not the Enthusiasm Gap. Today's Rasmussen polling shows that, incredibly, despite continued incompetence by the McCain campaign and more Obama hype, the two are tied. However, McCain pulls 85% of Republicans while Obama only polls 77% of Democrats--an 8 point difference. This is consistent with other polling that shows McCain drawing more support from Republicans than Obama can from Democrats--despite the "enthusiasm gap".

I have several theories for this development:

It's normal--In the last election Bush got more support from Democrats than Kerry got from Republicans. However, in that election the difference was slightly less--4 points.

The bases have changed--There are less Republicans and more Democrats than 2004, meaning that the Republican base is more "concentrated" with partisans while the Democrats have swelled to include independents who are only lukewarm to them.

Obama still is a drag on white working class voters--This is supported by Obama's relatively poor performance among Democrats in polls in Ohio, where the latest Rasmussen one shows Obama capturing only 74% of Dems while McCain gets 88% of Republicans.

In any case, I think this is more substansive than any "enthusiasm gap" that the candidates have. Of course, the media probably will continue ignoring it since it would inconvenience the narrative of Obama being a uniter when he can't even unite his own party.