Two weeks ago, Labour’s lead over the Tories fell several points over a weekend. It’s still big enough to give Labour a decent majority, but it’s the first sustained shift of this size since the Tories’ omnishambles last spring.
There’s been some speculation about why the polls changed. Was it because Thatcher’s death reminded a bunch of people that they loved the Tories after all; because the welfare debate hurt Labour; because Tony Blair was nasty about Ed Miliband in the New Statesman; or was it the belated unwinding of the gains that Labour made in 2012?
The reason the question of why it happened is important* is that some changes are only temporary – usually when there’s been an external news story or a well-received political setpiece. But politics news that says something new and fundamental about one party can produce a more lasting realignment. This is what happened after the omnishambles budget – and it’s what some are saying is happening to Labour with the welfare debate (in a bad way).
Firstly, on the headline numbers, there was a drop in Labour’s lead between the 12th and 15th April. Excluding a couple of outliers**, Labour went from 11.4 ahead in the YouGov*** polls before that weekend to 7.5 in the polls since then. While Lib Dem and UKIP scores haven’t changed much, the Tories have gone up a couple of points and Labour have fallen about the same amount:
The detail of who has switched might give us a clue about why things have changed.