WASHINGTON -- Bernie Sanders said Wednesday that Hillary Clinton is not "qualified" to be president, a sharp escalation in rhetoric in the Democratic primary.
"Secretary Clinton appears to be getting a little bit nervous," he told a crowd in Philadelphia. "And she has been saying lately that she thinks that I am 'not qualified' to be president. Well, let me, let me just say in response to Secretary Clinton: I don't believe that she is qualified, if she is, through her super PAC, taking tens of millions of dollars in special interest funds. I don't think that you are qualified if you get $15 million from Wall Street through your super PAC."
Clinton campaign surrogates responded quickly on Twitter.
"Hillary Clinton did not say Bernie Sanders was 'not qualified.' But he has now -- absurdly -- said it about her. This is a new low," campaign spokesman Brian Fallon tweeted.
Clinton was asked Wednesday morning by MSNBC whether she thought Sanders was "ready to be president."
"I think he hadn't done his homework and he'd been talking for more than a year about doing things that he obviously hadn't really studied or understood, and that does raise a lot of questions," Clinton said. "Really what that goes to is for voters to ask themselves can he deliver what he's talking about."
Sanders and Clinton are barreling toward the New York primary later this month, and the duo are increasingly tangling in heated, tense campaign trail exchanges.
Sanders' comments in Philadelphia were just the latest escalation in recent days. Clinton and her allies have been highlighting a recent Sanders interview with New York Daily News interview that was widely panned, suggesting it showed him unqualified for the White House.
In Philadelphia, Sanders turned that critique back on Clinton.
"I don't think you are qualified if you have voted for the disastrous war in Iraq. I don't think you are qualified if you have supported virtually every disastrous trade agreement which has cost us millions of decent paying jobs," he said to applause.
"I don't think you are qualified if you've supported the Panama free trade agreement, something I very strongly opposed and, which as all of you know, has allowed corporations and wealthy all over the world people to avoid paying their taxes to their countries."
Comments from the Daily News interview also drew attacks over Sanders' stance on guns from Erica Smegielski, a Clinton supporter and daughter of the Sandy Hook Elementary School principal who was killed at Newtown. Clinton highlighted the criticism by tweeting at Smegielski.
@EricaSmegs remember, any hateful comments are just noise compared to your voice for change. With you in the fight to stop gun violence. -H
— Hillary Clinton (@HillaryClinton) April 6, 2016
The latest Quinnipiac poll of New York Democrats finds Clinton beating Sanders 54 percent to 42 percent. That survey came out March 31, several days before Sanders won the Wisconsin primary. In fact, Sanders has won seven of the last eight Democratic contests, though Clinton has a commanding lead among delegates.
In addition to a trove of delegates New York is an important symbolic contest. Sanders was born in the Empire State, and New York City has been at the center of the national political battle over income inequality -- a signature issue for the Vermont senator.
But Clinton represented the state in the Senate, and her campaign headquarters is based in Brooklyn.
The candidates will face off in a debate in New York on April 14.