(CNN) Building a wall on the border with Mexico and deporting all undocumented immigrants has become an applause line at Donald Trump's rallies and the main policy idea for the GOP front-runner. But Trump's promise has sparked fear and frustration among farmers around the country, who, like it or not, depend on immigrant labor. "I'm angry," says dairy farmer Mike McMahon, who owns 700 cows in upstate New York, which is now the third-largest dairy producing state and the biggest producer of greek yogurt in the country. "For someone like Trump or Cruz to say they are going to send them all back is short-sighted because so much of our food supply is dependent on their labor," he said.Donald Trump has promised to depart all undocumented immigrantsDairy farmers say this could hurt the nation's milk supply
Trump's campaign declined to comment for this article and _'s did not respond to a request for comment.