Zimbabwean President Robert Mugabe walks with a guard to be sworn in for a sixth term in office in Harare, on June 29, 2008 after being declared the winner of a one-man election. (Photo credit: Alexander Joe/AFP via Getty Images)ONE OF THE GREAT HEARTBREAKS of the Trump era for me is seeing my expertise as an Africa analyst become relevant for understanding political trends in America. For example, when I read Jonathan Rauch’s essay on Trump’s a…