Did this prevent a Tory majority?
It has long been the case that in American elections, incumbency has been an important factor. Until fairly recently, that was not considered to be the case in British elections. While it was acknowledged that Liberal Democrats could build up sizeable personal followings, the general view was that it was a very minor factor in the far more numerous Conservative/Labour contests.
This view must now be challenged, judging by the results from May 6th. Overall, in seats where Labour had a majority of 14% or less, in 2005 (the seats that the Conservatives had to win to achieve a majority) the swing from Labour to Conservative was 6%, 1% higher than the national average.
However, in seats which were being defended by Labour incumbents, the swing was reduced to 5.3%, whereas in seats being contested by new candidates, the swing was 7.3%.
This may not appear to be a huge difference, but it matters enormously in marginal seats. To put it into context, had Labour kept the swing down to 5.3% in all of these marginals, they would have lost net 9 seats fewer to the Conservatives, almost certainly sufficient to have made a coalition with the Liberal Democrats a distinct possibility. Had the swing been 7.3% across the board, then the Conservatives would have won an outright majority.
Striking differences can be seen in the same towns, between incumbents and non-incumbents. For example, in Milton Keynes North, where the incumbent was a Conservative, the swing to the Tories was 9.2%; in Milton Keynes South, where the incumbent was Labour, the swing was 6.2%. In Swindon North, where a new Labour candidate stood, the swing was 10%. In Swindon South, where the MP ran again, the swing was 5.5%. Most notably of all, perhaps, in Luton South, the swing to the Conservatives was 4.6%, while Luton North, where the sitting MP had distinguished himself during the expenses scandal, showed a rare swing to Labour of 0.5%.
Equally clearly, Conservative MPs who were elected for the first time in 2005, enjoyed a notable boost. On average, they enjoyed a swing of 7.5% in their favour, well above average. Were the pattern to be repeated with Conservatives elected for the first time on May 6th, Labour would need a big swing in their favour before they could expect to regain a substantial number of seats from the Conservatives.
As has been the case for some time, there was a substantial difference in the outcome where Liberal Democrat incumbents were defending seats, and where they stepped down.
Overall, Liberal Democrat incumbents suffered a swing against them of 0.6% to their nearest challenger, on average. New candidates suffered a swing against them of 5.1%.
Admittedly, this average conceals some huge variations in individual seats. Tim Farron, in Westmoreland & Lonsdale, enjoyed a swing of 12% in his favour; Lembit Opik in Montgomeryshire, suffered a swing against him of 13%.
Clearly, there is also a reverse incumbency effect. Many MPâ€™s who had been heavily criticised, such as Lembit Opik, Jacqui Smith, Tony McNulty, Ann Keen, and David Heathcote-Amory, performed significantly worse than their parties did in their region. Equally, MPâ€™s such as Kelvin Hopkins, Nick Palmer, Vernon Coker, Sara Teather, Grant Shapps, and Justine Greening, who were seen as effective, strongly outperformed their parties.
This must surely be a healthy development. MPâ€™s who work well for their constituents ought to get an electoral reward. MPâ€™s who donâ€™t, should not expect to be automatically re-elected.