The second of four British debates are being televised tonight, with conservative Tory leader David Cameron trying to take down Liberal Democrat Nick Clegg, who squashed him in last week's opening debate. It's the first time the British parliamentary system is adopting U.S.-style televised debates, and it's been a boon for the libs. Post-debate surveys have shown that viewers widely prefer Clegg after the event, to the point that the Liberal Democrats are almost on par with Cameron's Labour party in polls of debate watchers. That doesn't mean Democrats are ahead in polls of the population at large — analysts say the gains the Democrats made during the debates won't necessarily reflect wider gains for the Democrat party during the next election. But it could make a difference.