New York may not be the nation's capital, but it's the center of the world. Just listen to the ultimate New Yorker at peak bravado, full of the parochial egotism familiar to any longtime resident.

"We have the greatest values — nobody has values like us," Donald Trump, the Republican front-runner, told his fellow New Yorkers. "And I'm proud of New York and I'm proud of the people of New York. And you know what? The whole country and the whole world is proud of New York. I'm telling you that — I know it. I'm all over the world."

As the nation focuses on New York and its presidential primary, it's highlighting the foibles and peculiarities of not just the candidates themselves, but on the challenges of campaigning in the Empire State, where authenticity is prized above all.

"Resiliency is a big issue for New York — you've got to be able to take a punch, and stand up and defend yourself," said George Artz, a Democratic strategist who was press secretary for former New York City Mayor Ed Koch. "Politics is blood sport in New York. We're all spectators and we all love it."

Trump is using his home-field advantage to take out his aggression on Ted Cruz after a bruising loss to the Texas senator in Wisconsin. The favorite son is hammering away at Cruz's attempts to disparage Trump and his "New York values."

But it's the Democratic race here between former Secretary of State Hillary Clinton and Sen. Bernie Sanders, two candidates with starkly contrasting personalities, that is boiling down to their own highly calculated displays of authenticity.

The high-profile two-step — gaffe swiftly followed by tabloid shaming — is an unwritten but ubiquitous step in New York's political process.

There was the time Democratic presidential candidate George McGovern was mocked for ordering a chopped liver sandwich and glass of milk at a kosher deli. Gerald Ford lost the state in 1976 after the New York Daily News summed up his refusal to bail out the city from bankruptcy with the headline: "FORD TO CITY: DROP DEAD." Ohio Gov. John Kasich was mocked for eating pizza with a fork.

Clinton earned some digs when she appeared in Brooklyn with Puerto Rican singer Toby Love, struggled to swipe her subway card during a planned photo-op and made the obligatory cheesecake stop at Junior's in Brooklyn.

The tabloids have been even tougher on Sanders, who stumbled through an editorial-board meeting with the Daily News when he struggled to provide details about how to break up the nation's biggest banks. The newspaper endorsed Clinton.

Cruz has been doing everything he can to walk back his "values" jibe. He visited a matzo bakery in Brooklyn, singing along to a Passover song. He tried to explain away his comment by saying he was talking about liberal Democratic policies.

Cruz could have learned from Kasich, who opened his meeting with the Daily News editorial board with a blend of astonishment and praise for the city. "I love being here. I just love being in New York. It's so crazy, right?" Kasich said at the outset of his meeting. "In New York City? Me? Running for president? It's hard to believe."

Two days later, the newspaper endorsed him.