Sean Trende analyzes elections for RealClearPolitics. Here he looks at the Cantor and Graham reelection campaigns - one successful, one not - and tries to suss out what worked and what did not. Unsurprisingly, he finds that the key variable is whether or not the politician in question kept firmly in mind as his first goal getting reelected - keeping the folks at home happy. Graham did, Cantor did not.
Can it be this simple, or is there truly some underlying theme at work here? There is no agreement on the answer to that question. I expect COTTonLINE will revisit the issue more than once between now and early November.