• When do losing candidates withdraw from the race?

The point at which a candidate withdraws varies, depending upon the candidate’s political platform, the possibility of his or her winning, and financial considerations. Presidential candidates who fare poorly in caucuses or primaries, particularly in their home states, traditionally withdraw from the race and urge their delegates to instead support another candidate, usually the leader. As a result, official voting at the party convention tends to be close to unanimous.

• Where do nomination races stand now?

In a largely unpredictable political environment, the January 3 Iowa caucus will be crucial. Currently, polls indicate Hillary Clinton, Barack Obama and John Edwards to be in a three-way tie among Democrats, while Mike Huckabee and Mitt Romney are the main contenders on the Republican side. Clinton and Obama are also tied in New Hampshire polls for Democrats, while Romney appears to be leading Rudy Giuliani among Republicans. Nationally, Clinton leads Obama by a wide margin, while Huckabee and Giuliani lead other Republican candidates.

The writer researches US foreign policy towards South Asia in Washington DC