Bernie Sanders held his ground Thursday morning in an increasingly bitter battle with presidential rival Hillary Clinton, saying \u0022this campaign will fight back\u0022 in the face of attempts by the former secretary of state to \u0022disqualify\u0022 him.The latest skirmish began Wednesday morning, when Clinton was asked point-blank by \u0022Morning Joe\u0022 host Joe Scarborough whether Sanders was ready for the Oval Office. As Politico notes, \u0022While Clinton did not specifically call Sanders unqualified...[she] declined three times to say whether her opponent had the proper pedigree.\u0022The Washington Post, among other publications, wrote about the exchange under the headline, \u0022Clinton questions whether Sanders is qualified to be president.\u0022Meanwhile, CNN reported Wednesday that with the campaign now focused like a laser on New York\u0026#039;s April 19 primary, Clinton\u0026#039;s new strategy with regard to Sanders is: \u0022Disqualify him, defeat him, and unify the party later.\u0022On Wednesday night, Sanders set off a firestorm when he responded in remarks at Temple University: \u0022She has been saying lately that she thinks I am quote, unquote \u0026#039;not qualified\u0026#039; to be president. I don\u0026#039;t believe that she is qualified ... if she is, through her super PAC, taking tens of millions of dollars in special interests funds.\u0022\u0022I don\u0026#039;t think that you are \u0026#039;qualified\u0026#039; if you get $15 million from Wall Street through your super PAC,\u0022 he said. \u0022I don\u0026#039;t think you are \u0026#039;qualified\u0026#039; if you have voted for the disastrous war in Iraq. I don\u0026#039;t think you are \u0026#039;qualified\u0026#039; if you have supported virtually every disastrous trade agreement.\u0022This was Sanders on Wednesday evening:Despite the media frenzy generated by the remarks, Sanders did not back away from his argument during a Thursday morning press conference in Philadelphia.\u0022If you want to question my qualifications,\u0022 Sanders said, flanked by labor leaders at the Pennsylvania AFL-CIO\u0026#039;s annual convention,then let me suggest this: Maybe the American people might wonder about your qualifications, Madam Secretary, when you voted for the war in Iraq—the most disastrous foreign policy blunder in the history of modern America. They might want to wonder about your qualifications, when you supported virtually every trade agreement—trade agreements which are costing the American worker millions of decent paying jobs. The American people may want to wonder about your qualifications when you\u0026#039;re spending an enormous amount of time raising money for your super PAC from some of the wealthiest people in this country and from the most outrageous special interests.\u0022Look, let me be clear,\u0022 he added later. \u0022This is not the kind of politics that I want to get in.\u0022\u0022But,\u0022 he continued, \u0022let me also be very clear. If Secretary Clinton thinks that I just come from the small state of Vermont, \u0026#039;they\u0026#039;re not used to this\u0026#039;... I\u0026#039;m not going to get beaten up, I\u0026#039;m not going to get lied about. We will fight back.\u0022Watch the press conference below:For her part, Clinton tried to pivot to the general election, telling reporters on Thursday morning, \u0022It\u0026#039;s kind of a silly thing to say. I don\u0026#039;t know why he\u0026#039;s saying that, but I will take Bernie Sanders over Donald Trump or Ted Cruz anytime.\u0022However, as Kevin Gosztola wrote Wednesday at Shadowproof, \u0022the Clinton campaign and media outlets like CNN promote a false narrative that the campaign has not been in attack mode. Since September, she has used a network of surrogates and rapid response super PACs to push anti-Sanders talking points into the media.\u0022\u0022Voters have yet to see the full scope of what the Clinton campaign will sling at Sanders,\u0022 he argued, \u0022but [Wednesday\u0026#039;s] interviews indicate she will return to her effort to paint Sanders as a gun-lover. She will focus on the fact that he is an independent senator, and, therefore, he is not a Democrat who will help the Democratic Party win in down-ballot elections in November. She also will attack him on regulating \u0026#039;too big to fail\u0026#039; banks and re-up her artful smear that Sanders has no respect for President Obama.\u0022If Gosztola turns out to be correct, Sanders remarks on Thursday indicate he won\u0026#039;t take it sitting down.Supporters of both candidates have been tweeting under the dueling hashtags #TakeItBackBernie and #HillarySoQualified:#HillarySoQualified Tweets#TakeItBackBernie TweetsThe candidates will face-off in person for a CNN-moderated debate on April 14 in Brooklyn.