So the Lib Dems have turned into the Tories and the difference is that rather then implode with internal pressure they have felt the squeeze externally from the Tories and Labour repositioning themselves. After all, they came second in the last two by-elections, and won a seat in Gordon Brown's backyard.

But that and the media infatuation with Mr Campbell’s age, he was 64 but if you didn’t know you could be excused for thinking he was 84, and the lack of genuine TV charisma resulted in one poor opinion poll after another. The policies the Lib Dems championed from the Iraq war, opposing the detention without trial to taxing pollution, have been stolen and adopted by candidates and causes across the political divide. Yet with the resurgent Tories and the indecision by Brown meant that a principled man with big ideas but without the X factor couldn’t withstand the snipping from within his own party.

And so a good man is down, and the political kaleidoscope that is in flux over the last month has been given another shake. The Tories plan of retaking their lost seats (which are still marginally held by the Lib Dems), could come unstuck by changing to a charismatic Leadership and the inner city voters and in particular Muslims who abandoned Labour, voting for the Lib Dems, are still swing voters and Labour are desparate in trying to reconnect.

In his stressful time for the Liberal Democrats the last thing they need is to get a habit of regicide, a taste of blood, intrigue and usurpation. It's like a sip of Coke, once you have a bit you want more. Opinion polls and external factors and charisma notwithstanding the Liberal Democrats must remember opinion polls can go up and down, seats stolen from the Tories can be lost in a tight election, but their position as an important, loud and brave Liberal voice must not be drowned out by ambition that could make Lady McBeth seem restive.

With the dignified resignation of Ming Campbell the political elites of Westminster have gone out of their way to heap praise on a deserving, principled political leader. The fight for succession, the two front runners in Nick Clegg and Chris Huhne, are preparing their campaign teams. Both have a stronger TV persona then Mr Campbell but both lack the every-man qualities of Charles Kennedy and the gravitas of Paddy Ashdown. Both have made positive comments on Palestine with Nick Clegg by far the stronger candidate on this voting issue for Muslims and both could lead the Liberal Democrats in a hung parliament.

The road will be awkward for the party members and they cannot make another mistake in selection, yet cannot afford to have another acrimonious selection campaign. They have to choose carefully and focus on ensuring that they are still seen as an alternative principled voice, with impeccable credentials and valuable new policies. There will be a temptation to chase ratings and become blander and react to the perceived wishes of the marginal seats they want to keep. If they produce a national background noise to wow those voters they may lose the gains they have made in Labours heartlands. The temptation will be there but to follow it would be wrong and ultimately disastrous. They can’t compete with Labour or the Tories for sheer media power, they can’t compete with the Tories on the right wing agenda, and Labour on the left win. What they can do however is make enough seats, both big city and small parish marginal, on issues like climate change, unfair taxes, pension reform, police reform, positive immigration, a positive ethical foreign policy, argument after argument, debate after debate and remorselessly pull the big parties into the deep and drown them.

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