In reply to JMW the 'normal politics' I had in mind was actually not having a Coalition government at the next general election.
However I take your point that we haven't really been in a state of 'normal politics' in the UK for quite a few years. UK mainstream politics has been stuck in the so-called 'centre ground' for about 15 years or more. Many people might say that all this started with Tony Blair and his 'New Labour' project, a centre ground version of the Labour party that is similar to the Lib Dems. But the Daily Mail's Peter Hitchens used to claim that the Blair government was just the Major government 'with go-faster stripes', implying this style of politics may have actually started up in the Major years. David Cameron has certainly bolstered up centre ground politics even further. Back in 2006 Nigel Farage of UKIP observed that the three main political parties were effectively all social democrat parties, with policies so close 'that you can't get a cigarette paper between them'. The main way out of the centre ground political fashion might be through the rise of UKIP, as you say, but I think if Scotland becomes independent next year that might also help, as it would make the Conservatives a bit more confident about winning a general election on their own.
Incidentally I've always thought that the biggest pusher of centre ground politics in the UK is someone who is largely unrecognised for doing so, Ian Hislop, who has appeared on the BBC's "Have I got news for you" for just over twenty years. I came to the conclusion that Hislop had in effect the biggest political influence in the UK about ten years ago. I was surprised to see the assistant editor of the Guardian, Martin Kettle, express a similar view a couple of years ago:
Hislop's satire is basically the Sensible party versus the Silly Party (for people familiar with the lengthy old Monty Python sketch), where the Sensible party is the centre ground (which is defined by the Lib Dems in the UK), and the Silly party is anybody who deviates from the centre ground. It doesn't surprise me that the era of centre ground politics in the UK seems to coincide with the continuous TV exposure Hislop has been given by the BBC. If I was involved with the BiasedBBC blog, I would have been campaigning against Hislop for years, but I don't think they really notice him because he's not pro-Labour. A public service broadcaster like the BBC should really be doing everything it can to encourage the citizens of the country to vote, and providing Hislop with a TV platform is in my opinion inconsistent with that. Hislop promotes a cynicism about politics which contributes to the low voter turnout.