Which polls?
ICM have had the Tories approximately 4% in the lead, that could be enough. A few weeks ago they had the Tories 6% in the lead, that's almost certainly enough. To go from 4% lead to a 6% lead is a 1% swing (Tories up 1, Labour down 1 is a 1% swing). A 4% swing would put the Tories 12% in the lead and would be a landslide. Last time Tories got a 7% lead but due to advantages in the system for Labour, Tory votes are less efficient. This time Tory votes are more likely to be more efficient (due to UKIP taking votes but not seats off the Tories in safe Tory seats for example).
As for where a swing could come from, there's a few answers for that. The polls frequently underestimate the government, in a landslide election that doesn't matter but in a close one it does.
Except the arguments made were largely the arguments made for (and against) PR. Yes PR wasn't on the table, but it was what most of the arguments were about at the time - and what was argued against at the time. I thought that was stupid, but it was the case and the status quo was supported overwhelmingly against change.Randblade, do you think I'm stupid or something and am going to fall for this level of drivel?
In the referendum, AV was rejected. Not PR. Not some other system. Just AV. Nor did the question on the referendum rule out any further referendum or any other changes to our current system in perpetuity. Come on, man.
As soon as it was over, rather than acknowledge the public had decided to reject change and keep the status quo the argument instantly became that the public rejected this change and we should just do it again. Maybe without asking the public next time, in case they get it wrong again. That is hubristic and wrong.