New York’s Republican presidential primary is turning into a fight over whether front-runner and hometown favorite Donald Trump can win with more than 50 percent of the vote.

“If he doesn’t get over 50 percent, he should probably consider dropping out, like everyone else has when they don’t win their home state in a dramatic fashion,” said Joe Roe, campaign manager for chief Trump ­rival Ted Cruz.

A conservative business group that bankrolled anti-Trump ads in Wisconsin also said 50 percent is the litmus test for Trump.

“If Trump gets less than 50 percent it’s a loss, he shouldn’t be the nominee,” said David McIntosh, president of the Club for Growth.

But Trump state co-chairman Carl Paladino said Cruz is a “fool” who “should go back to Texas before he embarrasses himself.”

He predicted that Trump would dominate all parts of the state.

The Real Clear Politics average of recent polls shows Trump ahead in New York with 54 percent, followed by 21 percent for John Kasich and 20 percent for Cruz.

Under the state’s primary rules, Trump has to win at least 50 percent of the vote in all of the state’s 27 congressional districts to win all 95 delegates.

Three delegates are distributed to the winner of each district, with 14 going to the overall victor.

But if a candidate wins with less than 50 percent, he gets two delegates and the second-place finisher gets one.

Trump has 746 delegates of the 1,237 delegates needed to win the nomination outright.

He would have to win 61 percent of the remaining delegates.