I once read a description of Labour voters from a Labour MP - they are mostly unheard and unseen, but come election day they descend like a mist and then they're gone.
No main stream media outlet speaks for them, no serious newspaper gives them voice, consequently their numbers are often underestimated.
Day after day the media hammer Ed Miliband, and whether you agree with it or not and his personal rating is terrible, Labours lead wobbles, drops a point here and there but basically holds, Labour needs 36% to win and it's achievable. The Tories, however, need 40% to win, they got 36% in 2010, they're between 28% and 32% now (no party has ever increased their popularity in office) and no Tory party has had to face a UKIP strength party to its right.
The figures are not just tough for the Tories, they're appalling, it is impossible to imagine them, in any scenario, getting an overall majority, that's why Hague has gone off to write and so many Tory MPs are standing down.
The Tories couldn't win a majority against a deeply unpopular Labour government led by Gordon Brown, they had everything going for them but still fell short, this time the only thing they've got is Ed's unpopularity that's why they keep plugging away at it, but poll after poll show its not enough. Defenders of the Tories say the polls narrow as the election looms and they do, but not for the Tories.
In a recent poll 40% of the electorate say they would never vote Tory, only 25% say the same for the Labour, in the poll tightening last stretch Labour swims in a deeper and wider pool. Demographics are doing for the Tories what it's doing for the Republicans in the States, huge swathes of the country are no go areas and increasingly whole age groups, the Tories know this, that's why they're playing to their core vote, they know it's over, for them it's not storming to victory time, it's just hanging on to what they can time.