Politics of tribalism in US presidential race

THE coming American presidential campaign - starting with the Republican and Democratic primaries early next year - was supposed to revolve around Big Issues, with Republican and Democratic candidates debating the major domestic and foreign policy dilemmas facing the United States.

Against the backdrop of growing international instability and new threats to US security interests, what should be the direction of US policy in the Middle East (or toward China, Russia, etc)?

Is the promotion of free trade, including the passage of the Trans-Pacific Partnership (TPP), in US economic interests?