It's worth pointing out that this election ought to demolish the Myth of Karl Rove. From the GOP perspective, while losing five senate seats is worse than losing four, losing six is much worse than losing five. Since the 2006 climate clearly wasn't favorable to the Republicans, the obvious thing to do would have been to concentrate resources on Republican incumbents running in red states -- Virginia, Montana, Missouri, and Tennessee. I feel like there's good reason to think the GOP could have won two out of those four had they focused. Instead, they tried an ambitious strategy of picking off Democratic seats in New Jersey and Maryland, two solidly blue states.
Interestingly, Rove made the exact same error in 2000, engaging in an absurd late-game effort to campaign in California. He then lost the election, only to wind up with Bush securing the White House through a series of incredibly unlikely events plus a partisan Supreme Court. Then in 2004, he did something similar with weird last minute gambits in Hawaii and New Jersey that put his candidates perilously close to losing Ohio (and with it the presidency) not withstanding a decent-sized popular majority. Learning nothing from his good fortune except an unhealthy sense of infallibility, he proceeded to do it again and then, finally, have things genuinely blow up in his face.