I interpret that to mean that they basically got tired of the Beltway mindset that much of the GOP establishment had assumed, and that many simply stayed home after McCain’s botching of the bailout. But that’s only my assumption, in looking at Rasmussen’s polling - Rasmussen also has Dem self-identification sinking like a brick as well, because neither party is identifying well with flyover country folks, hence the size of the Tea Party movemement. I haven’t seen post-mortem polls regarding the 2008 elections, but I would guess the RINOs were the ones who crossed over for Obama in larger numbers, whereas conservatives voted for McCain because of Palin or just stayed home.