Eastleigh: have voters found a new party of protest?

So the polls have closed in what’s been the most fascinating by-election for many a year.

Now there’s always a temptation for us political hacks to exaggerate the importance of certain elections, and yet there are several ways in which Eastleigh could be seen in years to come, as something of a historic turning point. Tonight’s result has big implications for each of the parties, depending, of course, on what exactly that result is.

Eastleigh by-election – reaction and analysis

We should remember it’s a Liberal Democrat seat, and the Lib Dems and their Liberal predecessors haven’t lost a seat they already hold in a parliamentary by-election since Carmarthen in 1957. But for Nick Clegg and his party to triumph in the current circumstances would be an incredible boost, what with their national polling figures down to below half what they got at the 2010 general election, and of course the Lord Rennard scandal which has dominated politics for eight days now.

But the Lib Dems in Eastleigh are among the best-organised local parties in Britain, boasting all the local councillors and they’ve run Eastleigh district council since 1994, when they first took the parliamentary seat. Victory here would bear out what I’ve been saying for several years – that the Lib Dems won’t be wiped out at the next election. Where they are strong locally, they will be very difficult to dislodge in 2015.

In a way, a Conservative defeat might easily be shrugged off. After all, a governing party has only GAINED a seat in a by-election three times since the war – Sunderland South (1953); Brighouse (1961) and Mitcham and Morden (1982), and each time the Conservatives were the beneficiaries. But this was the Conservatives’ big opportunity to get one over their coalition colleagues – hence David Cameron making two visits here, which I think is the first time a sitting PM has ever done so.

If Maria Hutchings loses tonight, especially if she does badly, David Cameron may end the week as a more beleaguered party leader than Nick Clegg. The discontent on the backbenches will grow and the pressure on George Osborne to produce a radical, exciting budget in three weeks time will be all the greater.

Labour, too, has a lot at stake here. The party hoped that Eastleigh would show that it could win back significant support in the south, and indeed one of Labour’s key proponents of a southern strategy, John Denham, an MP from nearby Southampton, has been running Labour’s campaign here. With an economy flat-lining, the reduction in Britain’s AAA credit rating, and the party doing well nationally in the polls, surely this was the chance for Labour to make an impact? Just as it did in the 1994 by-election when they came second to the winning Lib Dems, and in the 1997 election when they were second again (at the peak, of course, of Blair and New Labour).

A miserable result will inevitably raise questions about whether Labour can win significant numbers of seats in the south, and whether Ed Miliband‘s “one nation” approach, and Ed Balls’ economic policies are working.

But the most dramatic story in Eastleigh has been Ukip, who look set to achieve their highest ever vote in a Westminster election, surpassing the 21.7 per cent they got in Rotherham last autumn. I’ve been struck talking to voters this week by the high levels of support for Ukip from people who’d cast their votes right across the spectrum – defectors from the Conservatives, Lib Dems and Labour.

And the high level of Ukip support is all the more remarkable given the fact that David Cameron promised that if he gets a majority in 2015 he’ll give an “in-out” referendum on Europe.

Whether or not they win here, Ukip has been breaking important new ground in several ways. It’s now become acceptable and respectable to vote for Ukip in a way that wasn’t quite true a year ago. Many voters were reluctant to contemplate Ukip as they were thought to be oddballs, or in David Cameron’s phrase “closet racists”.

And the respectability for Ukip is reinforced by the growing willingness of the broadcasting community to treat Ukip as one of the “major parties”. We saw it with our Channel 4 debate on Monday, in which their candidate sat alongside the old three parties. The question is whether Ukip will carry on getting seats at the broadcasters’ debating table between now and the 2015 election.

And that brings us to one of the stories of this by-election – the willingness of some Lib Dem voters to switch to Ukip. It seems incongruous given Ukip’s emphasis on the EU and immigration, on which the Lib Dems are Ukip hold very different views. But what’s happening is that people who backed the old party of protest, have now found a new one.

I’ve no idea what will happen in the next few hours. But I guarantee the outcome won’t be dull.

Follow @MichaelLCrick on Twitter.