So David Cameron and Nick Clegg have finally crossed, if not swords then at least feather dusters, in public over electoral reform. Both made speeches on Britain's now-certain alternative vote (AV) referendum on 5 May.
"It's no secret that the prime minister and I come at this from different directions," Clegg earnestly explained. "On this one, I don't agree with Nick," said Cameron, crisper, more demotic and wittier than his deputy. Typical Dave.
But who is listening at this stage of their 11-week campaign, other than activists and the converted in both camps? And, if the open-minded were listening, what should they make of the speeches?
Cameron's was the easier task. It may be hard to defend the status quo when politics enjoys a low public esteem that long pre-dates the scandal over MPs' expenses and hangs over most elective western democracies, whichever voting system and scandals they sustain.
But in AV, the No campaign has a target many in the Yes camp have derided in the past as unsuitable and – Clegg's own much-quoted words – "a miserable little compromise". Cameron cited them again, along with the dismissive comments of Lord Roy Jenkins (AV might increase, not reduce, distortions) and a leading Yes campaigner, Labour's Ben Bradshaw.
The prime minister did not defend the status quo. He knows voters are angry with the political class. His remedy – "real reform", he called it – is fixed five-year parliaments, more equal-sized constituencies, stronger powers for backbench MPs, a right of recall for voters, fewer MPs (but not ministers), lower pay, harder work.
Oh yes, and "real empowerment" for communities, councillors and individuals via the Eric Pickles localism bill. Will voters buy it? Not if the reaction to Pickles's cuts programme or Caroline Spelman's plans to sell off the nation's forests is any guide.
So Clegg has a chance to persuade voters that AV, though not perfect, will give them more control over politics by making sure "every vote counts" as it does not, reformers argue, in safe seats under first past the post (FPTP) voting.
By requiring candidates to appeal beyond their tribal party interest and to win 50% of the local vote, once second and subsequent preferences have been counted, it will also make MPs work harder for their electorate, he said again.
It is the sort of thing Lib Dem MPs, famous for "pavement politics" on their patch, passionately believe. MPs with safe seats – Tory and Labour – often neglect their voters and there was a strong correlation between such seats and expenses fraud, he argued.
Such arguments explain why so many MPs in both larger parties dislike Liberal Democrats more than they do each other. "How dare they claim that, the self-righteous prigs," they murmur. Yet this is not meant to be a party political referendum. "I am not a politician," the fertilisation pioneer, Lord Robert Winston, said at the No campaign's launch this week – though he actually takes the Labour whip.
In reality, the AV issue splits all parties as fundamental controversies, Europe being the most familiar, often do. But most Tories seem hostile, and Ed Miliband has nailed his colours to the Yes camp's mast, hoping to persuade Lib Dem voters of his own non-tribal credentials against the hope that, after the 2015 election, they may prefer to get under the duvet with him instead.
They would be much happier, most Lib Dem MPs admit.
That argument plays both ways. The Labour Yes campaign issued a briefing paper to show why Cameron is "so desperate" to defeat the Yes vote – because in every election bar one since 1983, the Tories would have had fewer seats under the AV system.
Indeed. The exception is 1987, when Margaret Thatcher's huge 397-seat haul in the Falklands election of 1983 slipped to 375 under first past the post (FPTP), but would have been 381 under AV modelling.
Unstated by the Labour Yes camp, though Cameron's speech drew attention to it, is that Labour's great majorities under Tony Blair might have been bigger, too.
Is that a reason for backing AV, because it may prove to be an anti-Tory mechanism? Voters will have to decide. In truth, no one can be certain how voters would behave, except to be confident that they will not do what parties want them to do.
Thus Cameron conjures up a picture of "how to vote" fliers being handed out at polling stations, telling people precisely what order in which to cast their votes for maximum effect – not so much voting in droves as drones, he quipped. Most Australians (along with Fiji and Papua New Guinea, it uses AV) want to go back to FPTP, he claimed.
There will be plenty more such mind-numbing claims and counter-claims as 5 May looms. Others argue that tactical voting barely exists in Australia, unlike Britain. A letter-writer to the Independent says Lib Dem candidates may gain in weak areas – no longer a "wasted vote" – but suffer in areas where they are currently strong as voters spread their wings and vote for other parties.
Clegg said FPTP was fine for the long years when up to 97% of voters (1951) backed either Labour or Tory and the old Liberals had just six seats, five of them courtesy of a local pact with the Tories (he did not admit).
In 2010, that share was barely two-thirds. Lib Dems, nationalist parties (his list omitted the DUP, Sinn Féin and the BNP), the Greens and Ukip have all benefited.
Cameron countered that Caroline Lucas (31%) might not have won the four-way marginal of Brighton Pavilion for the Greens under AV – one of several try-ons in his own speech, which included the improbable claim that Gordon Brown might still be PM if AV had been in place last year.
He made a stronger point in saying that AV does not give "equal "votes because the second preferences of minor parties – BNP or Monster Raving Loony – can end up counting for more than those of major party backers, and be used to elect bland, second-rate compromise candidates over controversial ones, too.
That happens under any system. Indeed, Cameron's strongest point was that FPTP usually delivers a clear result – Thatcher in 1979, Blair in 1997 – when voters feel a tired government needs to be voted out. That does not happen under even slightly proportional systems like AV, he said.
Pro-reformers and those bored voters who enjoy the excitement of a change will brush such talk aside. "Under AV, there need never be another wasted vote. It means you can feel confident voting for the person or party you want to win and not have to think tactically about who can win," Clegg claimed.
To which Cameron's private response will probably be: "Duh?" Clegg says: "It's evolution, not revolution." Cameron says: "AV will make politics less accountable." And so on.
Both made valid points, both made some that reflected naked self-interest. Neither can be sure how change would really affect their prospects. They will struggle to keep up voter interest as the rival attractions of the royal wedding and the Champions League loom larger.
But, for political anoraks, Christmas is coming early this year.
