 In tonight's interview, the president refused to commit to a neurological test or some other cognitive test to assure the American public that he is fit enough for four more years in the White House. Lawmakers return to work here on Capitol Hill next week, where we'll be watching to see if his performance in tonight's interview is enough to silence some of the calls for him to step aside in his bid for re-election. Reporting in Washington, Drew Wilder, NBC News.