Donald Trump leads the Republican presidential field in polls of GOP voters nationally and in most early-voting states, but some surveys actually may be understating his strength. With Trump dominating political debates in both parties, gauging his true level of support has become a crucial puzzle. A new study of survey data by Morning Consult, a polling and media firm, provides one piece of the solution, although many uncertainties remain. The firm looked at an odd occurrence that has cropped up repeatedly this fall: Trump generally has done better in online polls than in surveys done by phone/Tribune News Service. More here.