Republican Donald Trump and Democrat Hillary Clinton are hoping their local ties will translate into important wins that could seal their front-runner status as New Yorkers head to the polls to vote in the state's delegate-rich primaries.

Mrs Clinton was twice elected senator for New York, while Mr Trump was born in the New York City borough of Queens and lives in a building bearing his name in midtown Manhattan.

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Even before the New York results are in, Mrs Clinton's campaign was declaring the Democratic race virtually over and warning rival Bernie Sanders that he risked damaging the party's eventual nominee if he keeps up harsh criticism of the former secretary of state.

The Herald: Democratic presidential candidate Hillary Clinton, left, greets supporters with her husband and former President Bill Clinton at a Nevada Democratic caucus rally (AP Photo/John Locher) (58414519)

Clinton campaign manager Robby Mook said Mr Sanders faces a "close to impossible path to the nomination" and predicted New York would result in Mrs Clinton taking "an important step to the nomination".

Mr Sanders needs to win 68% of the remaining delegates if he hopes to clinch the Democratic nomination.

For Mr Trump, the biggest question is whether he captures more than 50% of the vote statewide, which would put him in a strong position to win all of the state's 95 Republican delegates. The delegates will select the Republican nominee at the party's national convention in July.

Mr Trump closed his New York campaigning with an evening rally in Buffalo, where thousands packed the city's hockey arena to catch a glimpse of the billionaire businessman.

A big win for Mr Trump is crucial if he hopes to clinch the nomination before the party's convention in July.

The Herald: Republican U.S. presidential candidate Senator Ted Cruz is accompanied by his wife Heidi as he speaks about the primary election results in Florida, Ohio and Illinois during a campaign rally in Houston, Texas March 15, 2016.  REUTERS/Trish Badger  EDITORI

If the race is not settled by then, he faces the very real prospect of losing to Ted Cruz, whose campaign is mastering the complicated process of lining up individual delegates who could shift their support to the Texas senator after the first round of convention balloting.

Mr Cruz, who criticised Mr Trump's "New York values" earlier in the primary campaign, was bracing for a tough showing in the state, where some polls show him running in third place behind Ohio governor John Kasich.

Mrs Clinton's campaign has cast New York as a make-or-break moment for the Democratic race. A loss in her adopted home state would be a devastating political blow. But a big win would bolster her delegate lead over Mr Sanders and put her closer to becoming the first woman nominated for president by a major political party.

The Herald: Democratic presidential candidate Bernie Sanders acknowledges his supporters on arrival at a campaign rally.

Mr Sanders has stayed stubbornly close to Mrs Clinton, rattling off a string of wins in recent primaries and caucuses. But unless he can topple Mrs Clinton in a state like New York, he faces increasingly limited opportunities to change the trajectory of the race.

While polling shows Mrs Clinton with a comfortable lead in New York, Mr Sanders held out hope for a closer race.

"This is a campaign on the move," Mr Sanders shouted to a crowd of thousands gathered along the waterfront in Queens, the Manhattan skyline serving as a dramatic backdrop. "This is a movement getting the establishment very, very nervous."

Among Democrats, Mrs Clinton has accumulated 1,758 delegates to Mr Sanders' 1,076. Those totals include both pledged delegates from primaries and caucuses, as well as superdelegates, the party insiders who can back the candidate of their choice regardless of how their state votes. It takes 2,383 to win the Democratic nomination.

Mr Trump leads the Republican race with 744 delegates, ahead of Mr Cruz with 545 and Mr Kasich with 144. Securing the Republican nomination requires 1,237 delegates.