It is extraordinary how much the political mood has changed in recent weeks.

Until fairly recently the winner of the next General Election was a hotly debated issue.  Now people are treating a Conservative victory as a foregone conclusion.  People have forgotten how unclear things seemed just a few months ago.  In today's Guardian Peter Wilby's premise is not only that Labour will lose - but that they were always going to:

"a Conservative victory at an election in 2009 or 2010 was always likely as part of the cycle of democratic politics." (Peter Wilby - Labour has much more to lose than just the next election)

As the title suggests, he not only sees the next election as a loss for Labour - but has doubts whether they can win the one after that.

What are the Lib Dems to make of this this climate?

With a recent by-election in mind some will wonder whether Clegg will be subject to a Crewe-like squeeze across the country.

In 1997, on the back of a massive national swing to Labour, the Lib Dems gained nearly 30 seats from the Conservatives. But Labour's sweep was so strong that the Lib Dems lost some held held seats like Rochdale to Labour.  Blair was also able to win several seats from third, leapfrogging the Lib Dems in places like Conwy, Falmouth and Cambourne, Hastings and Rye and St Albans.

At the next election there's every reason to expect Lib Dem seats fighting Labour will benefit from a big Conservative swing.  But the Conservatives will also be challenging hard in Lib Dem held seats. The electoral arithmetic shows that there are a third fewer seats that the Lib Dems are in second place to Labour now (103) than they had against the Conservatives in 1997 (158).

The Crewe results don't mean that the Lib Dems can't make gains.  But the ability to defend held seats will be crucial in ensuring that gains from Labour won't be offset by losses to the Conservatives.