It is a good question to ask, but the Guardian is obviously incapable of sensible analysis. Larry Ellott also asks: whether the prime minister be another moderniser who arrives in power bouncing with optimism but for whom it all goes wrong? He goes on to say:
There are differences as well as similarities: Heath presided over a largely pro-European party and considered his greatest achievement to be Britain's entry into what was then the European Economic Community. Cameron leads an overwhelmingly Eurosceptic party and would like a less binding relationship with the European Union. Heath would have signed up to the euro without question; there is no earthly chance of Cameron taking Britain into the single currency.These "left-wingers" just don't do subtlety. Theirs is a monochrome world of black and white. It is no wonder they are so ill-tempered – they must be bored witless.
Thus, to the average Guardian reader, Cameron is a right-wing eurosceptic leading an "overwhelmingly Eurosceptic party". Dialogue is impossible. There is no meeting point, or frame of reference from which we can start.