The old politics.
Back in the good old days, all were agreed - the Liberals or their successors were the dirtiest campaigners out there. Whether Tory or Green, whether Nat, Labour or Socialist, this was part of the shared understanding of politics.
Although the Conservatives have now made this Faustian pact, in 1990 that sleazy old fascist Alan Clark summed up the old politics thus.
"The trouble is, once the Libs get stuck in, really stuck in, they are devilish hard to dislodge. Their trick is to degrade the whole standard of political debate. The nation, wide political issues, the sweep of history, forget it. They can't even manage to discuss broad economic questions, as they don't understand the problems - never mind the answers.
"The Liberal technique is to force people to lower their sights, teeny little provincial problems about bus timetables, and street lighting, and the grant for a new community hall. They compensate by giving the electorate uplift with constant plugging of an identity concept - no matter how miniscule - to which they try to attach a confrontational flavour: 'Newton Ferrers Mums outface Whitehall' and a really bouncy commonplace little turd as candidate, and they're in."