When Robert S. Mueller III, the first special counsel to investigate Donald J. Trump, concluded his investigation into the ties between Mr. Trump’s 2016 campaign and Russia, his report raised questions about whether Mr. Trump had obstructed his inquiry. Four years after Mr. Mueller’s report was released, Jack Smith, the second special counsel to investigate Mr. Trump, added new charges on Thursday to an indictment over his handling of classified documents, setting out evidence of a particularly blatant act of obstruction. 214