david malpass. from geopolitics to domestic politics, the presidential campaign was a huge story in the second half of this year. and it promises to be the biggest of 2016. john harwood joins to us help us look back at some of the big political stories of the past year. is what we're seeing on the campaign trail signaling a lasting change in our system, john? it seems so polarized more so maybe than ever. >> it's extremely polarized but donald trump is really a phenomenon we haven't seen before. totally unconventional candidate. way outside the norms of in terms of his behavior, his rhetoric. what we've seen from other candidates. so i think the question of lasting change depends on how lasting donald trump is. a lot of people, myself included, did not expect him to be the force that he ends the year as. but we'll see when we get close, february 1st is the iowa caucuses, february 9th is the new hampshire primary when the real votes getting cast is donald trump still going to be in the thick of it? t