Has the political landscape truly changed? Or are we just experiencing a blip? There has been a wobble-inducing shift in the polls since the budget, and for a couple of moments we have even seen UKIP sneaking ahead of the LibDems. Is this the start of a Conservative calamity, with a serious possibility of a split on the right, as my colleague Peter Kellner has contemplated, akin to the split on the left that saw Margaret Thatcher triumph even when there was an anti-Thatcher majority?

This is always the fundamental question: is the change we are experiencing part of a significant long-term trend, or will normal conditions soon reassert themselves? Success or failure often depends on making the right call.

Froth is the very stuff of politics. People get involved in the Westminster show precisely because they love the big game, turning minor spats into matters of historic importance. We are attracted to the drama of it, indeed we seem to need it to spur us into action. The electorate joins in as an audience, with pantomime booing. Over-reaction, volatility, is the norm. One hint that things have not really changed as much as commentators suggest is that in spite of the drop in Conservative support, people still rate Cameron more highly than Miliband, and prefer the Tories over Labour on the economy.

So one reasonable interpretation is that nothing has really shifted: people use mid-term elections (and polls) as a means of self-expression, and after all, their dominant view of politics is that it stinks. When it comes to making a real choice about things that matter voters pull back from their frustration. That’s one explanation for why Londoners might decide for Boris even though the capital is in a strongly anti-Conservative mood right now.

Maybe that’s too pat. Look back fifty years at the longer-term trends: in the past, the two main parties commanded ninety per cent of the vote. Whichever was the biggest of the two could be pretty sure of a governing majority. Now they can hardly manage eighty per cent, and need others for support. So, one might argue, the dynamics are indeed in long-term change. Because people no longer attribute much significance to the minor differences in policy, they feel free to use their vote any way they like. Centrist politicians get increasingly nervous of their ability to win majorities, they hold on to each other for survival ‘as two spent swimmers that do cling together and choke their art’. The politics of the future is understanding and overcoming this fracturing and clinging.

Well, there’s nothing inevitable about it either way, trend or blip. The one can become the other, depending on how the randomness of life is handled by those at the top. What we can say with some certainty is that the electorate values competence well above distinctiveness of ideas. Not many people ever credit politicians with having the right answers, only with not messing things up too much. The left and the right of the Conservative Party (or indeed the Labour or LibDem Parties) attacking each other is the best possible indicator of incompetence.

This classic ‘narcissism of small differences’ emphasizes the isolation of politicians rather than their common cause with the electorate. For lasting success, a politician must embrace his party and the nation as if they were the same thing. Competent management, unity of purpose, and clear communication of direction is what distinguishes success and failure.