There's a small, slim chance that low turnout could help the "Yes" campaign. Whilst it's easier to persuade people against AV and stick with status quo, it's also harder to mobilise voters to come out and vote against something than it is to mobilise keen voting reform enthusiasts to take their once in a generation opportunity. But, ultimately, not enough people care about the intricacies of their voting system to make such a mobilisation of popular support likely.
So, it will be a "No". If it is, the "Yes" campaigners should listen to the voters, not sulk away to lick their wounds. You cannot fight a campaign to improve our democracy and then not listen to the democratic will of the people.
Nick Clegg's words tomorrow will be important. He may try and blame the coalition's unpopularity, that it was a "referendum on difficult decisions taken in the national interest". I expect him to say a lot about respecting a democratic result. Being not a fan of AV himself, having called it a "nasty little compromise" he may well blame it on the wrong form of proportional representation being put to the test.
Whatever he says, he must say it carefully. I don't believe those who will say that this is voting reform put to bed for a generation. With a strong likelihood of another hung Parliament with Labour as the largest party, I think there is a good chance of there being another voting reform referendum - held in happier times, when talking about voting reform doesn't seem irrelevant to people's daily lives - within the next decade.
What will begin tomorrow is a new kind of coalition. Chris Huhne has used the AV campaign to mark himself out as a Cabinet rebel and a potential future leader. Both him and Vince Cable could trigger a coalition crisis if they judge that the coalition is all pain and no gain for the Lib Dems.
But Nick Clegg should stay the course. Lib Dems quitting the coalition would seem petulant and self-obsessed. We didn't get our voting reform, so we leave? Or we want a significant portion of our manifesto implemented (not all of it, coalition compromises don't allow that), and we need to be grown up members of government, taking the tough decisions to do that.
Five years is a long time. The Lib Dems - and I mean the likes of Cable and Huhne - need to remember that they should strive to demonstrate that coalitions work... that the Lib Dems have made a valuable Lib Dem contribution in government.
That demands patience and maturity from the would-be rebels. And the start of a new phase for Clegg in which he stamps out an unmistakably Lib Dem identity at the heart of government. Not propping up the Tories. But Lib Dems, in government, getting things done, getting things that Lib Dem voters at the last election wanted to see done.
Breaking up the coalition, not losing the AV vote, is what will really end the voting reform debate for a generation.