By Luciana Lopez and Jonathan Allen
NEW YORK (Reuters) - Presidential hopeful Bernie Sanders doubled down on Thursday on his assertion that his rival for the Democratic Party's nomination, Hillary Clinton, is unqualified to be president as the two campaigns became increasingly testy two weeks before New York's election contest.
Clinton, stung by a string of losses in other states, this week sharply questioned Sanders' credentials and ability to carry out a campaign pledge to break up the big banks.
Sanders, a U.S. senator from Vermont, told reporters in Philadelphia that Clinton had come after him in a "really uncalled-for way" and again questioned the Democratic front-runner's own fitness for the Oval Office.
"Are you qualified to be president of the United States when you're raising millions of dollars from Wall Street, an entity whose greed, recklessness and illegal behavior helped destroy our economy?" Sanders said at a news conference.
In what has become an increasing source of acrimony in the Democratic campaign, the former Senator and U.S. Secretary of State Clinton has angrily bristled at Sanders' repeated suggestion that the large amounts of donations she receives from the financial industry clouds her independence, a notion she ridicules.
Brian Fallon, a Clinton spokesman, said Sanders' 'unqualified' comment was a "new low" in the race.
The focus of Democratic and Republican Party campaigns to choose candidates to run in the Nov. 8 election for the White House has shifted to the April 19 primary in New York, home to Wall Street and two of the leading candidates: Clinton and Republican real estate businessman Donald Trump.
Trump canceled plans to campaign in California on Friday in order to focus on New York where he is hiring additional staff, his campaign said.
Trump has reminded Republican voters that Ted Cruz, a U.S. senator from Texas and Trump's nearest rival, has spoken derisively of "New York values", his suggestion being they are not American values.
The reminder drew boos from thousands of Trump supporters at Long Island rally on Wednesday night, followed by cheers as Trump described the bravery of city firefighters after the Sept. 11, 2001 attacks by Islamist militants that destroyed the twin towers of the World Trade Center in Manhattan.
SPOTLIGHT ON WALL STREET
For the Democrats, the New York-based financial industry was in the spotlight. Clinton has won significantly more votes so far, but Sanders is proving increasingly popular, with national surveys showing them both more or less tied among voters.
Sanders found himself defending his remarks on Wall Street in an awkward interview with the New York Daily News, the transcript prompting a wave of critical articles by political journalists this week.
Clinton, who represented New York as a U.S. senator for eight years, said Sanders seemed unaware in his answers of the details and implications of one of his signature policies of Wall Street reform, breaking up big banks.
Economists who support Sanders defended his answers as accurate, saying the interviewer appeared at times to confuse the Federal Reserve with the U.S. Treasury Department.
Sanders' interview drew criticism from other quarters. In an opinion essay in the Washington Post on Thursday, General Electric Co.'s chief executive, Jeff Immelt, defended his company against Sanders' suggestion it was an exemplar of corporate greed.
While sitting down with the Daily News, Sanders, a Brooklyn native, also revealed his mistaken belief that New York City commuters still had to use small metal tokens to ride the subway, a system scrapped in 2003.
Teasing this, Clinton invited a crowd of journalists to watch her use a digital swipe card at a subway station on Thursday morning.
"I think it was my first term when we changed from tokens to MetroCards," she told reporters, a dig at Sanders. When at the turnstile, however, Clinton experienced what many New Yorkers do every day - it took several swipes for the card to register and allow her to proceed to the train.
"If Secretary Clinton thinks that I just come from a small state of Vermont and we're not used to this, well, we will get used to it fast," Sanders said. "I'm not going to get beaten up, I'm not getting lied about. We will fight back."
Spokesmen for Clinton noted that Clinton never said the word "unqualified" when she questioned his preparedness for the presidency, but they declined to say if that is what she believed him to be.
But Clinton, ahead of her subway ride on Thursday, aimed for a more magnanimous tone than her aides.
"I don't know why he's saying that," she said of Sanders' calling her unqualified, "but I will take Bernie Sanders over Ted Cruz or Donald Trump any time."
(Additional reporting by Doina Chiacu, Megan Cassella and Amanda Becker in Washington; Editing by Jonathan Oatis and Grant McCool)