U.S. Senator Ted Cruz of Texas is getting a taste of the "New York values" he derided in Iowa as Republicans turn to the next big U.S. presidential contest in the home state of front-runner Donald Trump.

The New York billionaire lost the Wisconsin Republican primary on Tuesday to Cruz and is seeking to rebound in New York on April 19. He won the backing on Thursday of former New York Mayor Rudy Giuliani, who was irked by Cruz's values comments.

"It's New York City. We're family. I can make fun of New York but you can't," Giuliani, who led the city through the trauma of the Sept. 11, 2001, attacks, told the New York Post.

"I support Trump. I'm gonna vote for Trump," he said.

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Ohio Governor John Kasich, running third in the Republican race, chimed in with an ad called "Values," part of a seven-figure ad buy in New York and Pennsylvania, which votes on April 26.

"New Yorkers aren't stupid and they certainly won't fall for Ted Cruz's lame soliloquies and flattery after he slammed their values," said Kasich spokeswoman Connie Wehrkamp.

Trump canceled a Friday trip to California to focus on New York. He turned on Cruz Wednesday night during his first rally in the state since the double-digit loss in Wisconsin.

"I've got this guy standing over there, looking at me, talking about New York values with scorn in his face, with hated, with hatred of New York,” Trump said, drawing a chorus of boos.

Cruz credited his Feb. 1 Iowa caucuses victory in part to his attacks on Trump's "New York values." He told ABC on Thursday the phrase referred to the state's liberal Democrats.

Cruz took another hit in the Bronx, where a group of high school students protesting his stance on immigration threatened a walkout if their principal did not cancel his appearance.

"Most of us are immigrants or come from immigrant backgrounds. Ted Cruz goes against everything our school stands for," Destiny Domeneck, 16, told the New York Daily News.

School authorities complied, the newspaper reported on Thursday.