Topping the polls 2-4 weeks out is not always a guarantee of success – just ask Nick Clegg
This YouGov poll from April 20 2010
Coming top in YouGov poll 2-4 weeks before an election doesn't always guarantee success
This from April 20 20010 pic.twitter.com/edWWeX8fnw
— Mike Smithson (@MSmithsonPB) April 27, 2014