As the 9 million or so ballots from the Golden state were tallied, that argument quickly evaporated and the Donald Trumps head exploded (wishful thinking on that last part).

Nonetheless, Republicans still tried to maintain the lack of mandate argument based on the narrowed but still healthy majority they managed to win in the house of representatives. Unfortunately for John Boehner and his troops, a look past the surface reveals that even there, the GOP doesn't have a mandate to maintain the obstructionism of the past two years. 

The Republican majority in the house is the direct result of gerrymandering and the highly politicized process of drawing district boundaries. by getting control of so many state legislatures in 2010, Republicans were able to control that process (something Democrats are just as guilty of in the past and even now in places where they are in command).

As a result we have boundaries that are are arbitrarily drawn in such a way that pockets of opposing support are heavily concentrated in fewer districts. The remaining districts are drawn to ensure just enough of a Republican majority to almost guarantee that they will maintain a majority in the house for the next decade (until after the next census and subsequent redistricting). Of course the same thing has been done on the other side in order to ensure the likelihood of some African Americans in congress so there is definitely plenty of blame to go around. 

The bottom line this year is that the latest round of Republican-led gerrymandering has resulted in a mandate-less majority where they have a 233-194 advantage despite the fact that Democratic candidates collectively got 54,301,095 votes while Republicans got 53,822,442. 

Going forward, we need to find a way to take district drawing away from partisan politicians and make the process neutral.