It has been bad to see a minority of protesters (whether they were students or not) rioting, causing damage and injury. It meant that the BBC News at Ten led on the story of the attack on the car of the Prince of Wales and the question of royal security rather than the scandalous vote to allow universities to raise fees.
But David Cameron surely signed Vince Cable's fate when he patted him on the back when he sat down in the House of Commons after speaking in favour of the motion. 'Good man. You're one of us.'