Democratic political consultant Dan Payne has worked on presidential campaigns, including John Kerry's in 2004, when the tenor of the debates or decidedly more polite.
Thursday night's standoff between Hillary Clinton and Bernie Sanders seemed to break new ground on the contentious scale, with Clinton going after Sanders on guns and Sanders mocking Clinton's connections to Wall Street.
"I think it means that New York is becoming very important to both candidates," Payne said.
Polls show it's Clinton who is poised to win the New York primary letting up, but Sanders has survived this far by exceeding expectations, though many feel the delegate math no longer works for him.
Democratic political analyst Dan Cence says Bernie Sanders needs to ask himself how much longer he's going to keep it up for the good of the Democratic Party. And he says candidates need to be careful about being too rude, or to tough, or to negative.
Cence says, "when you attack really hard, it tends to lead to voter suppression more than it leads to someone changing their mind on a vote."
Maybe so, but neither Clinton nor sander show any signs of letting up. Dan Payne says the advent of social media plays heavily into the current tenor of the debate.