Overview: Friday on the NewsHour, President Trump suggests Congress repeal Obamacare, even if they can't craft a replacement. Sen. Roy Blunt weighs in on the health care wrangling. Also: Rebuilding a police force in one of the most violent U.S. cities, the president meets with South Korea's leader, Mark Shields and David Brooks take on the week's news and the dangers of relying on statistics in medicine.