I mentioned some examples of attacks targeted at Conservative candidates and campaigners – the racist defacing of posters, a swastika daubed on a house – a couple of weeks ago. I’m sad to report that there appears to have been an increase in such incidents, and also of vile dirty tricks, in recent days.

Charlotte Leslie has written for the Telegraph about vandals attacking her and her parents’ cars, and now flooding her parents’ garden with oil.

Cat Turhan, the President of Warwick Students’ Union (and members of the NUS “Welfare Zone” committee) has been gleefully publishing pictures of vandalised Conservative posters.

Search social media for a minute and you’ll find numerous examples of materials smashed, stolen or defaced.

Nor is the descent into deeply unpleasant behaviour limited to vandalism – over at PinkNews, Mike Freer alleges that some Labour canvassers have been raising the topic of his sexuality with Orthodox Jewish voters in order to deter them from voting for him.

It would be untrue to claim that Conservatives are the only victims of such behaviour: a UKIP supporter in Bournemouth was reportedly assaulted for having a poster outside his house, while the Cybernats’ aggression has spilled out onto Scotland’s streets, and in Bradford a jewish journalist critical of George Galloway reports being attacked by supporters of the so-called “Respect” party (a brand which could only be surpassed in irony if Frankie Boyle launched a public morals campaign called “Good Taste”).

Of course, the response of those who come under attack is the right one – to decide that the only way to defeat such tactics is to fight on in defiance of people who think attacks and intimidation are valid debating tactics. But we do have to ask how anyone in a democratic society could ever decide that acting in this way seems acceptable.

While no one party alone is subject to such behaviour, and I’m sure some Labour campaigns will have suffered vandalism in some places, it’s fair to say there appears to be an ideological trend. Overwhelmingly, the vandalism and intimidation appears to be targeted at the right – particularly Conservatives and UKIPers. This is the left’s hysterical rhetoric made flesh. After all, if it’s routine to accuse Tories of killing people by reforming welfare, or of “ethnic cleansing” for defeating the NUM, or of being “lower than vermin“, then they’re deserving victims of anti-democratic crimes, aren’t they? If your party of choice is “evil” then you’ve asked for it, right?

There are many decent people on the left who are horrified by both this rhetoric and the acts it inspires. But they are far from defeating the many others in their own ranks who think it’s legitimate action. When will the left sweep itself clean?