The Guardian has thoughfully offered all its ICM/Guarduan opinion polling figures for last 26 years in downloadable form for readers to mash up. So in the spirit of do-it-yourself quantitaive analysis, I decided to look at the 1984-2010 six month moving average. It offers some interesting historical perspective and a reminder (above) of how party fortunes fluctuate: the Lib Dems real high point in terms of support comes in the mid-1980s in the wake of the 1983 election when they are over 30% before crashing badly in the late 1980s following disappointing 1987 election results and a botched merger with the Social Democratic Party. The Lib Dems then recovered to 20-25 per cent, which has chararacterised their supprt up until the current election campaign. The moral? Perhaps that the Lib Dems are more likely in the current to be beneficiaries of protest vote and vague desire for change and reform rooted in David Cameron’s apparent failure to ‘seal the deal’.
The same moving average for ‘other’ parties (below) shows a more regular pattern of relentless increase in minor party support over the last quarter century driven – interestingly – but European elections- the peaks in the graph. This seems true before the introduction of PR, when he Greens got 15% (the first big spike)