NEW YORK — With accusations of lying, hustling for money and failed leadership, the race for the Democratic nomination took a decidedly negative turn, with Hillary Clinton and Bernie Sanders exchanging a series of barbs over qualifications for the presidency.

The testy exchanges underscored the heightened stakes for both sides as the race turns to New York, where Sanders hopes to turn his recent winning streak into concrete momentum toward the nomination. Clinton, meanwhile, is looking to the April 19 contest to take command of a primary race that many in her campaign worry will only amplify her weaknesses heading into the general election.

Sanders’ path to the nomination remains narrow: The Vermont senator must win 68 percent of the remaining delegates and uncommitted superdelegates if he hopes to clinch the Democratic nomination. That would require blowout victories by Sanders in upcoming states big and small, including New York.

Lagging in delegates and under fire from a frustrated Clinton, Sanders is shifting away from his pledge to avoid negative attacks and stinging her with direct accusations.

“I will not leave here this morning and go to a Wall Street fundraiser,” he told union members at an AFL-CIO conference in Philadelphia on Thursday. “I will not be hustling money from the wealthy and the powerful.”

The comment was a direct dig at Clinton, who was headed to Ohio and Colorado for fundraising after a campaign stop in New York.

“This is not the type of politics that I wanna get in,” he told journalists in Philadelphia. “But we’ll get used to it fast. I’m not gonna get beat up. I’m not gonna get lied about.”

Clinton sought to shift attention back to her Republican opponents, telling reporters Thursday, “I will take Bernie Sanders over Donald Trump or Ted Cruz anytime, so let’s keep our eye over what’s at stake in this election.”

The race for the Democratic nomination has remained relatively civil as compared to a chaotic and crowded Republican race colored by flagrant attacks.

Clinton has spent much of the past few weeks focused on Trump and Cruz, hoping to rally her party behind her by warning that a Republican president would roll back President Barack Obama’s achievements. But since Sanders logged a big win in Wisconsin on Tuesday night — his sixth victory in the last seven contests — she’s been forced to pivot back to her primary opponent.

A former New York senator, she’s been touting her work in Congress for the state, highlighting her economic record in visits to struggling upstate cities.

A Brooklyn native, Sanders left New York for Vermont in 1968. Still, he’s cast himself as a native son of the state, viewing the contest as a springboard into primaries along the Eastern seaboard.