Why is personal attack a left wing thing?

I must define what I mean. I am not talking about the sorry spectacle of Cameron coming close to calling Brown in liar in PMQ - there is very littler else he can do with a man who refuses to tell the truth which everybody knows.

I am talking about the smearing and innuendo where there is no evidence and the attacked person has little chance to rebut from evidence. We are here in the Damian MacBride area, who is reputed to have used invented alacious and scurrilous suggestions.

We have it in Harman with her "joke" about Osborne and lap-dancing, or Milliband's taunt of Tories consorting with Nazis. (The latter has been completely rebutted, and is based on the slurs of Macmillan Scott who denigrated a rival, and others, who do not like to think that there is any group who should be allowed to challenge the 'project' or construction. Macmillan-Scott, now cast adrift by the Tories, is in this an "honorary lefty".)

It seems that Labour will taunt the Tories for at least five months with "nasty", because one or two belonged to an unattractive undergraduate group 25 years ago, and with being children, that is inexperienced. They should be careful on both counts. Some now respectable senior labour figures, eg Dennis Healey, to name the very respected, belonged to the communists when an undergraduate, and considering the mess Labour have made and the turnover of ministers who were nearly all without experience of government, the taunt about experience is double edged.

So why do they do it? I suspect that it comes from an intolerance of conviction, that there is no alternative to their own philosophy and those who differ must be charlatans or worse. The intolerance even extends to debate - with Labour unwilling even to appear with and argue with another legitimate party the BNP. Their views are unacceptable to most people, so why not demolish them? So, I suspect that smear and innuendo is used when evidence is lacking, and where there are no counter arguments.

We face an interesting time before the election. Are we to have a highly personal attack with smear on opponents, or are we to have a serious debate on the future direction of our country? I fear that that for one party it may be the former, and I suspect that the public are wise enough to draw their own conclusions.