And Obama has identified a few issues that would draw him out directly: a Muslim ban, though he still considers the chances of that remote, or moves that would cut back on the protections he put in place for the children, known as “dreamers,” who were brought to the country illegally as minors and who’ve been living here since. “If he deports thousands of kids,” Obama has said several times in private meetings of late, according to people present, “I don’t know that I can sit on the sidelines.” Also potentially on the list: a move by Trump to unravel...