Barack and Michelle Obama closed out the Democratic National Convention’s second night by pitching Kamala Harris as an heir to their political legacy. And they derided Donald Trump as a “racist” egomaniac who’d squandered his own presidency, and needed to be kept out of power. “This convention has always been pretty good to kids with funny names who believe in a country where anything is possible,” the former president said in his closing remarks, an echo to the convention address that...