President Trump warned migrant families Tuesday that the best way to prevent losing their children is “don’t come to our country illegally.” “I have a solution — tell people not to come to our country illegally,” Mr. Trump told reporters at the White House. “That’s the solution. Don’t come to our country illegally. Come like other people do. Come legally.” He was responding to a question about how the government will reunite about 3,000 illegal immigrant children who were separated from their families at the southern border. “We have laws, we have borders. Don’t come to our country illegally. It’s...