Three candidates are bunched in second place
                                
                                
                                    (Newser) -
                                    For voters planning to attend Democratic caucuses in Iowa, at least, the presidential field is getting clarity. Joe Biden resides at the top, followed by a rung that includes Bernie Sanders, Elizabeth Warren, and Pete Buttigieg, a Des Moines Register/Mediacom/CNN poll shows. The former vice president has the caucus vote...