President Donald Trump rang in America’s 250th birthday celebrations with a 28-minute speech at Mount Rushmore and a fireworks display that might have rivaled his words. “The American dream still lives, and the American flag still flies more proudly than ever before over the people who will not quit,” Trump said at the end of his lengthy — albeit shorter than his usual hours-long — speech. “The nation that will not fail, the country that will not fall no matter how hard the enemy tries, we…