There is a myth that in 2012 the PCs won by getting vast numbers of Liberal and NDP voters to switch to the PCs, but the polling data doesn't back this up at all. If you look at polls over the course of the 2012 campaign the Lib and NDP vote was in the 10-12 range right from the moment the writ was dropped and never really budged. The NDP ended up going up 1% compared to 2008 and went from 9% to 10%. The Alberta Liberal support had already collapsed before the campaign even began from the 26% they had in 2008 to about 10%. I think that what happened was that two thirds of 2008 Liberal voters shifted to Wildrose at the start of the campaign because they just wanted to kick the PCs out and saw the Wildrose as being best positioned to do it. Those people ended up having second thoughts in the end , but they had already abandoned the liberals before the campaign had even begun.
It's not just since 2008 though. I think it's a common understanding that progressives in Alberta have backed the PC party for some time now to stop anything further right from governing.
