MILWAUKEE — Moments after a gunman shot Donald Trump in the ear, the bloodied former president raised his hand in defiance and mouthed the words, “Fight! Fight! Fight!” as Secret Service agents led him to safety. But at a Secret Service checkpoint leading to Fiserv Forum on Monday, where the first day of the Republican National Convention kicked off, demonstrators were angling for another kind of fight. “Fight, fight, fight, abortion is a human right,” the protesters chanted in an effort to make their faces seen and voices heard to the thousands of Republican politicians and convention delegat…