David Davis's resignation as Shadow Home Secretary and as an MP has been described by almost all political commentators as unprecedented. It is also pointless.
Cheering and rare as it is to see any politician so motivated by principle that he will sacrifice a flourishing career for it, it's hard to see what David Davis can possibly achieve by triggering a by-election.
He says he'll be standing to campaign against the Government's plans to be able to detain terror suspects for up to 42 days before having to charge or release them.
That, in itself, is a laudable aim. But even if Mr David stood and won back his seat with 100% of the votes, all it would indicate is that a lot of people in this country (or, rather, a lot of people in Haltemprice & Howden) agreed with him.
He says that would give him a mandate. But a mandate for what?
If Gordon Brown, realising that he'd won the Commons vote on 42 days through arm-twisting and horse-trading with those in search of political favours, had decided to resign himself and stand again to determine whether he had a mandate to press ahead with the policy, that would have been understandable.
Because if he'd won - "if" being the word, of course - he would at least have been in a position to do something about it.
David Davis isn't. Even with a mandate, he couldn't have done a thing about it even if he magically got his job back as Shadow Home Secretary.
David Cameron already agrees with him on 42 days. There isn't a vacancy for Tory leader, and isn't likely to be one.
So if Mr Davis does win his mandate and returns to the Commons, he'll be about as effective as an MP with a Chivers factory in his constituency who claims he has a mandate to raise the price of jelly.
The Government, unlike a jelly, is not expected to wobble.
The one factor that Mr Davis seems to have overlooked is that the Government's chances of getting the 42-days legislation on to the statute books are said to be very slim indeed, as the Lords are unlikely to pass it.
Yes, the Government could invoke the Parliament Act and push it through regardless of democracy, but Gordon Brown might well face a vote of confidence in his Premiership if he tried that.
So the only person whose resignation could have made a difference on this issue is still sitting comfortably in Downing Street, while David Davis, whose resignation won't make a blind bit of difference, has simply rocked the Tories' boat just as it seemed to be making full speed ahead for a landslide win at the next General Election.
David Davis may consider himself to be a brave if self-appointed people's champion, but Goliath's reaction so far appears to be a teenagerish "Whatever".
Jon McKnight