If the Lib Dems lose most or all of their MEPs in the European elections, and endure a similar thrashing in the locals, there will be calls from some in the party for Nick Clegg to resign as leader. With a year to go until the general election, there is still just enough time for someone else to take the reins and try and revive the party's fortunes.
But for several reasons, even in the event of a complete wipeout, Clegg is likely to survive. First, Lib Dems activists and MPs have been buoyed by the party's unashamedly pro-European campaign and will regard any defeat as an honourable one. "No one can fault Nick's efforts," one told me.
Second, Clegg's political godfather Paddy Ashdown has already moved to shore up his position, warning potential rebels that they will have to answer to him if they attack Clegg after the results. The Lib Dem leader's decision to appoint his mentor as the party's general election chair is regarded as a shrewd one. "Every time there's a crisis, Paddy's on the news channel", a party source notes. Just as Peter Mandelson came to Gordon Brown's rescue in times of trouble, so Ashdown serves as Clegg's political life support machine.
Third, the most obvious pre-election replacement for Clegg - Vince Cable - has seen his star wane over the last year, while other alternative leaders - Tim Farron, Danny Alexander, Jeremy Browne - are biding their time until after May 2015. They have no desire to lead the party into the toughest general election it has faced for decades.
But Lib Dem calculations aside, it's worth noting that both the Conservatives and Labour have an interest in Clegg's survival.
For the Tories, the danger is that Clegg's deposition would lead to the collapse of the coalition and an early general election. While some of David Cameron's MPs might welcome such an outcome, the PM certainly would not. Indeed, he and his staff are already preparing a "Save Clegg" operation for the aftermath of the elections, with a series of Lib Dem "policy wins" planned for the Queen's Speech on 4 June.
For Labour, the danger is that any replacement for Clegg would succeed where he has failed and revive the party's fortunes. As I've often noted, if Labour is to win in 2015, one of its most important tasks will be maintaining the support of the 20-25 per cent of 2010 Lib Dems who have defected. "We want to wound Clegg, not kill him," one Labour MP told me. In addition to those seats that Labour can hope to win directly from the Lib Dems, strategists point out that in 86 of the party's 87 Tory targets, the Lib Dem vote share in 2010 was larger than the Conservative majority. In 37, it is more than twice as large. Even if Clegg's party partially recovers before 2015, Labour stands to make significant gains.
Aware of this, some Tory MPs have long hoped that Clegg will be replaced by a more left-wing figure such as Cable or Farron who could persuade the party's former supporters to reutrn home. But fortunately for Labour, their wish is likely to be denied.