Democratic Minnesota governor Tim Walz unraveled at the vice presidential debate Tuesday night when asked to explain why he falsely claimed that one of his many China visits coincided with the Tiananmen Square massacre. “You said you were in Hong Kong during the deadly Tiananmen Square protest during the spring of 1989,” CBS News moderator Margaret Brennan asked. “But Minnesota Public Radio and other outlets are reporting that you didn’t actually travel to Asia until August that year. Can...