President Trump may be ready to intensify his antagonism of Muslims. Reports suggest that the White House is considering an executive order directing the State Department to assess whether the Muslim Brotherhood should be designated a Foreign Terrorist Organization. Some Republicans, including Trump’s erstwhile rival Sen. Ted Cruz (Tex.), have been pushing for this for a long time, and it will have ramifications far beyond the Middle East, where the group primarily operates. The result is likely to be intimidation, harassment and smears of Muslim and Arab groups here in the United States. The Muslim Brotherhood was founded in Egypt...