Donald Trump’s fired-up New York backers predict that a victory by him in November would set the stage for defeating Gov. Andrew Cuomo in 2018 — and lead to the ouster of their own GOP leader next year. They also predict that if the Manhattan developer becomes president, he’d work from the White House to turn New York away from the anti-business, tax-and-spend, “progressive’’ Democratic politicians, including Cuomo and Mayor Bill de Blasio, who now dominate City Hall and the state Capitol. The Trump supporters, who lost out Friday in an effort to convince state GOP Chairman Ed Cox to...