CLEVELAND — Hundreds of police officers, Secret Service agents and private security guards in cars, on foot and on horseback blanketed the area around Donald Trump’s campaign rally Saturday afternoon. Dozens of protesters would soon be ejected from the event. And that was the calmest rally in the past several days thrown by the front-runner for the Republican presidential nomination. Welcome to Trump’s new normal. After months spent goading protesters and appearing to encourage violence, Trump has seen his raucous rallies devolve over the past two weeks into events at which chaos is expected.