How did US politics get to this sorry state? America's political civil war began in the 1960s. The most notable feature is the rise of the New America - constituencies that used to be politically marginalised but have come to power with Barack Obama. They include new minorities (Latinos, Asian Americans), old minorities (African Americans, Jews), young voters, LGBTI, working women, single mothers, educated professionals and the unchurched (the nearly one in four Americans who claim no religious affiliation). Arrayed against the New America is the Republican Party, which has become a resistance movement. Republicans see Donald Trump as the un-Obama - a doer, not a thinker. What impact will this have on America's role in the world?

Listen back to our in-depth conversation with one of America’s leading US political analysts, Bill Schneider. He spoke with USSC chief executive officer Simon Jackman about the 2016 presidential race.

Circus Maximus: The 2016 US presidential race with Bill Schneider