President Donald Trump used a visit to the Justice Department on Friday to air a litany of grievances about the criminal investigations that threatened to torpedo his political career. He decried his adversaries in often profane terms and cast himself as a victim of unfair and biased prosecutions. He vowed retribution for what he described as the “lies and abuses that have occurred within these walls.” The speech was meant to rally support for Trump’s tough-on-crime agenda. But it also functioned as victory lap after he emerged legally and politically unscathed from two federal prosecutions that were dismissed after his election win last fall.