Donald Trump got more votes in the New Hampshire primary than the total votes collected by Cruz, Rubio and Jeb Bush. Republican party leaders don't believe that Trump can win in a general election and they were ready to converge on Marco Rubio until he crashed and burned in New Hampshire. That leaves them with Ted Cruz who could not win a general election, and Jeb Bush who has had problems selling himself to the GOP electorate.
Hillary Clinton's performance in Iowa and New Hampshire raises concerns about her ability to win a general election. Bernie Sanders has generated more enthusiasm than Clinton within the liberal wing of the Democratic Party. Nobody expected Sanders to do as well as he has and his performance in Iowa and New Hampshire will bolster his campaign going forward. Party leaders have to be concerned about a candidate, who describes himself as a socialist, in a general election.
The lackluster performance of establishment politicians in both parties may reflect a more general concern in the electorate. Neither political party seems to satisfy the concerns that bother their constituents. Donald Trump and Ted Cruz appeal to two different segments of the GOP base but that makes them vulnerable in general election. Bernie Sanders appeals to one of the mainstay segments of the Democratic base but he would be vulnerable in a general election. That leaves the party with a candidate that has yet to generate enthusiasm in her base and who has a track record in government that is open to attack. The electorate is searching for a leader who can address their concerns but our system has not produced that leader.