WASHINGTON — Hillary Clinton, the nearly unstoppable Democrat, and Republican front-runner Donald Trump accelerated Wednesday toward an increasingly direct path to presidential nominations after trouncing party challengers in New York.

Clinton, now 81 percent of the way toward clinching the Democratic nomination that eluded her eight years ago, can lose every remaining contest and still prevail. Her sweeping victory in the New York primary called into question the durability of Bernie Sanders’ rival campaign and left him with severely limited options for overtaking her.

While Trump strengthened his hand, he is still far from in the clear.

Trump is focused heavily on clinching the Republican nomination through voters’ balloting in state primaries, thus avoiding a contested national convention in Cleveland in July. The businessman’s win in his home state keeps him on a path to securing the 1,237 delegates he needs, though he’ll have to perform well in the round of primaries in Pennsylvania, Maryland, Connecticut, Rhode Island and Delaware on Tuesday and in California’s huge contest on June 7.

His chief rival, Texas Sen. Ted Cruz, has no mathematical path to getting the nomination through primary voting. But he sees a window to snatch the nomination from Trump at the convention, and his campaign is working feverishly to line up delegates who would support him if Trump fails to prevail on a first ballot.

The side-by-side GOP efforts at this late stage – with Trump amassing primary victories while Cruz digs for the support of delegates who could settle the nomination in a contested convention – are unprecedented in recent presidential campaigns and add to the deeply uncertain nature of the race.

Trump basked in the glow of his victory at a rally in Indianapolis, where he drew several thousand people to a packed building at the Indiana State Fairgrounds. He railed against the Republican nominating system, pointing to Louisiana, where he was outmaneuvered by Cruz in the fight for delegates, and Pennsylvania, where the statewide winner gets 17 delegates outright and the rest “are up for grabs.”

“They can take the delegates, they can put ’em in airplanes and fly ’em to resorts, they can have dinners with them, they can put them in hotels. Essentially what they’re saying is they can buy the election,” Trump said.

Indiana votes on May 3.

Cruz campaigned in Hershey, Pennsylvania, trying to brush off his Tuesday shellacking in New York where he failed to pick up a single delegate.

Clinton’s win in New York, a state she represented in the Senate for eight years, halted Sanders’ recent string of victories and put her in a stronger position heading into the next contests. She could lose them all and still win the nomination – if she did well enough to win some delegates.

Sanders offered no signs of giving up before the Democrats’ Philadelphia convention and plans to campaign in Pennsylvania on Thursday and Friday.

Clinton was holding events in the Philadelphia area, joining former Attorney General Eric Holder to outline her plans to curb gun violence.

On the Republican side, many party leaders are torn. Trump is seen by some as a threat to the GOP’s very existence. Others fear the party would implode anyway if Cruz were to overtake Trump through a bitter and complicated delegate struggle in Cleveland.

Ohio Gov. John Kasich, the only other Republican left in the race, picked up at least three New York delegates but still has only one primary win – his home state.

Trump’s campaign has struggled to keep up with Cruz in working the delegate system, deepening the urgency around his team’s efforts to clinch the nomination before the July convention.

Mindful of a need to avoid errors like the ones that plagued his campaign in recent weeks, Trump has hired a more professional political staff, been more careful on social media and infused his victory remarks in New York with flashes of policy proposals.

Associated Press writers Scott Bauer in Madison, Wisconsin, Steve Peoples and Thomas Beaumont in Hollywood, Florida, Jill Colvin in Indianapolis and Mark Scolforo in Hershey, Pennsylvania, contributed to this report.

Follow Julie Pace at http://twitter.com/jpaceDC and Ken Thomas at http://twitter.com/KThomasDC