Has David Davis lost it?

What on earth is David Davis up to? I'm buggered if I know. He says it is to protest against the “slow strangulation of fundamental British freedoms” by the Government. But his party voted against the 42 days didn't it? His constituency, Haltemprice and Howden, is a safe seat; at the last election he won 47.5% of the vote (22,792) and the Liberal-Democrats were in second place with 36.8% (17,676). The Liberal-Democrats are not going to stand a candidate in the by-election, so there seems to be no reason why Davis should not romp home. So what's the point? It obviously has something to do with Cameron's ascendancy. Davis - like Brown in 1994 - clearly thinks "it should have been me!". I presume has been cut out of Cameron's inner circle. Perhaps he suspects that, if Cameron wins the next election, he will be re-shuffled down (or out). Probably there is not much love lost there. But even so it all seems very odd. How it will help Davis's leadership ambitions (which is what this must be about) is beyond me. Has he gone bonkers? Gordon will be popping the champagne corks.