1. The Liberal Democrats are more resilient than generally assumed and are not doomed to inevitable electoral wipeout at the general election. Even though their share of the vote in national polls has halved since 2010, Nick Clegg is treated as a joke in certain sections of the media and some projections have claimed that they are on course to lose all their MPs in 2015, Eastleigh confirms that where they have a strong local organisation, they can win.

2. British voters are not certain to reject austerity in 2015. With real living standards falling for millions of people, and the coalition's economic policies failing to produce growth, some people assume that Britons will inevitably vote against austerity at the general election. Yet in Eastleigh one of the governing parties won, and the two coalition parties combined received 57% of the vote. Ukip did well by attracting a protest vote. But there is no evidence that Ukip voters were protesting about austerity.

Chris Huhne leaves Southwark crown court after pleading guilty to perverting the course of justice last month. Photo: Olivia Harris/Reuters

3. Voters do not punish parties for the misconduct of individual MPs. After Oldham East and Saddleworth, Barnsley Central, and Rotherham – byelections where the resignation of a Labour MP in disgrace did not stop the party winning again – this should be obvious. But, during the Eastleigh campaign, commentators regularly speculated about the impact of Chris Huhne's guilty plea on the Lib Dem vote. It was a waste of time. The voters did not seem to care, and the parties that tried to exploit this (as the Tories did half-heartedly) were wasting their time.

4. There are two one-nation parties in the UK, but neither of them are Labour. The two one-nation parties are the Conservatives and Ukip which are strong all over one nation (England) but have little support in the two others (Scotland and Wales). Labour and the Liberal Democrats are both three-nation parties, capable of winning in England, Scotland and Wales. Ed Milband, of course, defines one nation differently, but Eastleigh shows that he is some way off achieving his goal of making Labour a strong electoral presence in the south of England.

Ukip leader Nigel Farage. Photograph: Matt Cardy/Getty Images

5. Conservative attempts to counter the threat posed by Ukip are failing, and they don't seem to know what to do about it. When David Cameron promised an in/out referendum on Europe after 2015, there were claims that he had "shot the Ukip fox". But the Ukip fox has never been healthier, and Tory attempts during the campaign to counter Ukip by echoing their anti-immigration message - and even at one point putting out a Maria Hutchings leaflet in Ukip colours - did not work.

6. The Conservative brand remains tainted, despite Cameron's attempts to modernise his party. Labour campaigned by saying it was opposed to the Tory-led coalition, and the Lib Dems campaigned by saying they were opposed to the Tory arm of the coalition. But, interestingly, even Hutchings, the Conservative candidate, made a point of telling voters that she was "not a rich Tory toff".

The Conservative party candidate Maria Hutchings leaving the count at Fleming Park in Eastleigh early on Friday morning. Photograph: Chris Ison/PA

7. "Real people" and celebrities don't always make particularly good election candidates. The Tories tried to make a virtue of the fact that Hutchings was an outspoken mother and not a professional politician, but her lack of political sophistication may have done her more harm than good. Labour chose a metropolitan minor celebrity (albeit one with a strong activist record), but that did not seem to help either. Mike Thornton, a dull but experienced councillor, seemed to be the best candidate.

8. Organisation is the key to winning an election. There is nothing profound about this insight, but it's worth highlighting because it's easy to forget. The Lib Dems won because they are extremely well organised in the constituency, they knew who their supporters were, and they got them to the polls, or to submit postal votes (of which there were many, with the Lib Dems doing particularly well proportionately from them).

9. Lynton Crosby is not invincible. When Crosby was appointed as the Conservatives' election campaign director, he was written up in places as an electoral genius. He is certainly good, but Eastleigh shows that he's not invincible. (See note at the bottom of this piece.)

10. National Health Action does not (yet?) pose a threat to the main political parties. When the National Health Action party was founded last year, there was speculation that it could stage an election upset somewhere. The main parties remember with dread how Richard Taylor, co-leader of National Health Action, won Wyre Forest in 2001 and held it for nine years after campaign against a hospital closure. But in Eastleigh National Health Action were nowhere, with just 392 votes.



12.15pm update: Point 9 is unfair. I've just been told that Crosby was not involved in Eastleigh and that he predicted in advance that the Tories would lose.