Gordon Brown is resigning as Prime Minister, which means that the Tories and the Lib Dems must have an agreement in place by which David Cameron can form a government. So the Sturdy Golden Bear Party (blue + gold SEE WHAT I DID THERE) is ready to ride.
This is a huge, huge, HUGE gamble by Nick Clegg. The Lib Dems have a far stronger left-libertarian streak than Labour, especially since LibDem and Labor come to the left from two different-ish traditions. There might be common ground for the LibDems and the Conservatives on some topics, but not on a lot of things that matter – and matter a LOT to LibDem voters. Nick is going all in with Old Nick, so to speak, because this is the best chance the LibDems will ever have to force electoral reforms that could get them a more permanent place in government with an elected party commensurate with their percentage of the electorate.
But.
If the deal is for a referendum, they are screwed – Labour voters will not want to support a party that sold out to the Thatcherites, and Conservative voters will never support any mechanism that would make the Tories a permanent minority in Parliament (as any real proportional voting system will inevitably force). What they need to have is a commitment from a Cameron government to implement some sort of reform right up front, whether Instant Runoff (as seems most likely) or something else.
So yeah. This is a bet – that the future of the LibDem party can be staked on a deal with a Conservative government eager to push in the opposite direction of almost everything the LibDems hold dear. I stand by my prediction that we’ll have another election by Christmas – and that by then, Clegg and the Liberal Democrats may well wish they’d forced the Tories to govern as a minority government and held their cards until the next round.