The first real test of popularity is looming for America's Presidential candidates.

The crucial Iowa Caucuses take place later - the first vote in a series that will end with one candidate being elected to the White House in November.

Polls suggest that business tycoon Donald Trump has a lead over Ted Cruz and the other Republican candidates.

But the Democratic race is much tighter, with former US Secretary of State Hillary Clinton just edging ahead of Senator Bernie Sanders.

These people in Des Moines were keeping their views to themselves.