I don't think they paid much attention to Romney in the last cycle. The focus was then on McCain being a fraud since he was the frontrunner.
Note that I was NOT a Romney supporter in 2008. I'm just saying that I can understand why some people supported him back then but oppose him now.
There has been more publicity to Romney's negative actions during this election cycle. The Tea Party too took off in 2009/2010. In 2008, most people got information only from people like Sean Hannity and went along with them. Now people have realized that they can fight back.
Simply because Romney got away in 2008 does not mean that those who let him get away then are obligated to let him get away now.