Choice between principle or power is no choice at all. Whether a party of power or party of protest - we won't change the world unless we are a party of purpose. Yet too much now rests on being united by what we are not - mainly not being the Tories, sometimes not the nationalists, and God forbid the liberals. That does not make us the alternative government in waiting. It doesn't even really make us the opposition. It just makes us 'not them'.