But what about deeper change? Well, I can understand the argument – made punchily by Gideon Rachman here – that this will increase the likelihood of a hung Parliament. That's probably true. But there's also a chance that it might help the Tories pull clear of their opponents. It all depends on which party the Lib Dems suck voters from and, more importantly, in which marginals they do so. Or, of course, there's always the possibility that people were impressed with Clegg last night – but won't change their vote as a result. Either general ambivalence, or less convincing performances in the two remaining debates, could drag the Lib Dem leader down from the stratosphere again. We will need to wait for more polls – including the poll of polls that is the election – to find out.
And then there's the little matter of whether last night will help rejuvenate our democracy. On that front, the main thing which struck me about the debate was its civility and its clarity. Sure, there were confrontations and obfuscations aplenty. But, on the whole, this was politics played at a more edifying level than in PMQs each week, and several worlds away from the pervasive grubbiness of Westminster. If people tuned in, then they may well have been impressed by what they saw. It all depends on whether they tuned in – and we'll have viewing figures shortly.