Pour encourager les autres, you might think a rational Labour Party would now be showing any Tory waverer how welcome they would be. Alan Howarth, their prized Tory defector, would be decked in laurel wreaths and garlands, fatted calves would be slaughtered for him in barbecues up and down the constituencies. Above all, you would hope that he might land a safe seat.
But political parties are not rational - and many in the Labour Party have been giving Howarth hell. Some call him a carpet-bagger or a chicken- runner and they tell him to get to the back of the queue. They shake their fists in the air and declare that they will never forget that he voted for the poll tax, privatisation of British Rail and all manner of other outrages. Humble pie and a life-long penance are in order.
Maybe. These are heinous crimes, but on the other hand, might Howarth not bring with him a new tranche of Conservative voters? To be sure no- one would promise any old opportunistic defector a guaranteed safe landing, but Howarth is a prize fish.
But then grassroots party politics is less about winning than about a blend of fierce tribalism and vicious personal ambition. Nothing arouses this atavism more than defection. No one is as angry as a local Councillor Buggins afraid that some newcomer might winkle him out of the seat for which he has spent the past 10 years pounding the pavements trying to earn his selection. As the ideological dividing lines between the mainstream of each party fade into grey, so belonging to a party becomes more about the kind of people we are - clans, class, taste, self-image, heritage and roots. We're talking Man U vs Man City.
That is why crossing the floor of the Commons is so extraordinarily rare and difficult. Howarth is the first Tory MP to cross to Labour - and the way some in the Labour Party are behaving, there is a grave danger that he will be the last. If the reward for Howarth and Emma Nicholson - Tory defector to the Lib Dems - is instant political annihilation, the lesson will be learnt by other Tories with itchy feet and a guilty conscience.
Howarth, it is said, is not a very happy man, with few political friends. When I called top Labour apparatchiks, they said he was fine, just fine - but when I asked who his friends were, they were flummoxed. Several offered to call back with a name or two, but no calls came. (Howarth himself is in Chile this week - though no doubt if he were available he would protest that he is having a terrific time in his new party.) Of course Blair's people want him to be selected in a good seat, but the way things are going it may not happen. He is able, decent, assiduous and loves the House of Commons. (Odd but true.) He is sufficiently respected for even the Tory attacks on him to have been relatively muted. He may have a horrible past to live down, but in recent years he has been clearly a liberal and he has experience as a former minister for higher education.
Tribune, the "old Labour" weekly, has been hounding him since he arrived - gleefully encouraging his failure to get selected in seat after seat, while warning of "leadership conspiracies" to get him imposed on some unsuspecting party or other. "We get calls from local party people warning us if ever he sends in his CV," says Tribune's editor, Mark Seddon, malevolently. "There's a suspicion that some old-timer MP will retire just before the election, deliberately making no time for a selection so the leadership can impose Howarth. He came from the Thatcherite right and if he's ratted once, he could rat again. The rank and file who have done 15 or 20 years of legwork don't want to create some centre party where it doesn't matter where you come from." (Mr Seddon is himself on the trail for a safe Labour seat.)
What of Emma Nicholson? Of course she says she is having a wonderful time among wonderful people. The Lib Dems have been very nice to her and she feels absolutely at home - no complaints. But if I were her, I might have hoped for a winnable seat. More important, if I were a waverer from another party, I would be watching her progress with keen interest. But she has not applied for any seat - for family reasons, she says. (Others hint she knows her new party quite well enough to have decided from the start that it might be a waste of time and dignity.)
She now hopes for a European seat, fully aware that since her party only has two MEPs, finding a winnable one will be exceedingly difficult. Liberal parties have favourite sons like the bottom of a boat has barnacles. Will anyone stand aside for her for the good of the party? We shall see.
Ms Nicholson says gamely that of course she expects no help - "I joined a democratic party, so the membership decides." A tad fairer than the Tories maybe, but hardly what you would call "democracy". In all the parties a handful of activists who pay their subscription get to choose the candidate on behalf of the rest of us. Some democracy.
Our method of selecting MPs locally often favours a local grandee or councillor over superior merit, party or national interest. It produces a House of Commons three-quarters stuffed with the stupid, the venal, the idle and the mediocre - lacklustre local chaps (mostly men) with no qualification for governing the country. Currying favour with local activists by clocking up leafleting hours is not a qualification for power - especially as local activity has virtually no effect on general election results. Once selected, too many will plant their bottoms on the green leather benches for 20 or 30 years of wasted space.
At every election the whole country swings in unison, voting for central government regardless of the calibre of the unknown person we are obliged to vote for locally. That near-universal voting pattern exposes the myth of the "local" MP. If Alan Howarth does not succeed in winning some constituency, it is to be hoped he will lose to a succession of much better people.
But if the last 23 or so winnable seats for Labour reject Howarth for lesser candidates, then it really is time to find a better way. We should have primaries and a form of proportional representation that allows selection from a list. The MPs we have now are neither representative nor a brightest and best elite.