Gideon Rachman makes the connection:
Events in both Pakistan and America suggest what happens when you not only disagree with your political opponents but when you demonise them as enemies of the faith or the nation. At that point, some may conclude that it is legitimate to end the argument with bullets.
[Y]es, America could become like Pakistan if people concluded that it was legitimate to settle arguments with bullets. But in America, where guns are plentiful and political and religious feelings intense, the telling thing is that almost no one at all considers political violence to be legitimate. The killings have been met with universal condemnation by ordinary Americans and the whole political class. The violent act of one probably deranged individual doesn't show that America is heading down the same road as Pakistan. And the response to it suggests that the political cultures of the two countries are fundamentally different.