Lewandowski appeared on Fox News Channel tonight to discuss Trump's child-snatching border policy with Democratic strategist Zac Petkanas. As the latter was talking about a young girl with Down Syndrome who had been separated from her mother by authorities, Lewandowski – who Trump is eyeing to replace John Kelly as White House Chief of Staff say some – could be heard snarking, "whomp, whomp." “Did you just say ‘womp-womp’ to a 10-year-old girl with Down Syndrome being…