Winning 68% of the electoral college sounds like a landslide to me.
It's all perspective. Your perspective is comparing it to other larger blowouts. Also, consider the fact that Clinton was aided by third party candidates. For me, anything over 60% sounds like a landslide. Yet if you look at the popular vote, it is not as big. It all depends on what you are looking at.
An electoral vote landslide, but not a popular vote one. Even 1980 was not referred as a landslide in some quarters.
As to the mandate, 2010 and 2012 will express how much of a mandate there was.
