Just as teenagers forbidden to see each other become more determined to pursue their romance, so being in a hated party excites activists because of the feeling that “They” don’t want you to succeed. “They” means the main parties, who want to keep the electoral battle between the two of them, and their allies in the press. That’s why Nick Clegg relishes attacking the cynics who claimed the Coalition couldn’t work – there were indeed plenty of cynics, but he also knows that wheeling them out in almost every speech is catnip to his activists.