The closer Britain gets to election day, the more uncertain things become. One uncertainty, however, seems to have been cleared up - Gordon Brown and the Labour Party are out of contention.
The first debate resulted in Nick Clegg and the third place Liberal Democrats surging into close competition with David Cameron's Conservatives for first place. And while Cameron got a bit of a boost in the second debate, Clegg was able to maintain his rising status. As for Brown, he's now seeing some of Labour's lowest poll ratings ever, and he seems to be losing any chance of winning the most seats despite finishing third in the popular vote.
Furthermore, in an interview with the BBC's Andrew Marr, Clegg has now declared Labour "irrelevant" and that he will not (as many thought) form a coalition with Brown if Labour wins the seat-count but comes third in the popular vote. This smashes the chance of a "Lib-Lab" coalition and kills the meme that "a vote for Clegg is a vote for Brown." Right now, the British press is interpreting these moves as a hint that Clegg prefers Cameron's Conservatives as a coalition partner - but I think they're at least partially wrong.
From my vantage point, something more sinister seems afoot. Cameron has regained a slight lead in the latest polls, but Clegg is right on his heels and needs just a slight boost to take the lead. With Labour in free-fall, Clegg can now move to collapse the Labour vote entirely by convincing voters that Gordon Brown is a lost cause. If he can do that, he becomes the only viable candidate on the left, and could slingshot into the lead as strategic "Stop Cameron" voters flood into the LibDem camp.
Now that he is clearly in contention, Clegg seems to realize that his easiest path to victory is not to stand back and mock the two traditional parties. Instead, he can bludgeon the flagging Labour Party to death and unite the left behind the Liberal Democrats. If he goes into the final debate declaring "Labour is dead, only I can stop Cameron," he might just convince the Labour base to put their own party out of its misery.
The irony here is that, in normal elections, the LibDems crash at the last minute because strategic voters shift to Labour to avoid vote-splitting in favor of the Conservatives. So, Clegg must be relishing the opportunity to use the vote-splitting argument to shove the final knife in Gordon Brown's back.