For many Lib Dems, last night's by-election defeat feels like a victory. They may have finished 3,558 votes behind Labour (having been just 103 behind at the general election) but their share of the vote rose to 31.9 per cent. That is of significant comfort to a party that has been as low as 7 per cent in recent national opinion polls. The fall in the Tories' share of the vote from 26.4 per cent to 12.8 per cent suggests that it was tactical voting by Conservatives that compensated for Lib Dem defections to Labour.
David Cameron's decision to wish the Lib Dems well and the Tories' half-hearted campaign undoubtedly persuaded many Conservatives to back Nick Clegg's party. A pre-election Populus poll showed 22 per cent of 2010 Tory voters defecting to the Lib Dems and, given the collapse in the Conservative vote, the actual figure is likely to have been higher.
What few have noted is how this affair bolsters the case for electoral reform. Had the Alternative Vote been used last night, Tory supporters would have been free to vote for the Conservatives as their first preference, safe in the knowledge that their second-preference votes would be redistributed to the Lib Dems.
The conservative case for AV has been made by few outside of Phillip Blond's ResPublica, but I'd expect this to change as the referendum draws closer. Others, like Boris Johnson, who declined an invitation to join the No to AV campaign, have become agnostic about reform. Rather than any formal pact between the Tories and the Lib Dems, AV may yet offer the coalition its best chance of sticking together.