Trump's White House campaign faces first test in Iowa

By John Whitesides DES MOINES, Iowa (Reuters) - Donald Trump's ground-breaking White House campaign faces a moment of truth on Monday when Iowa voters begin the nationwide process of choosing a new U.S. president, with polls showing him in a tight battle with Ted Cruz to be the Republican nominee. On the Democratic side, front-runner Hillary Clinton is hoping to fend off a stiff challenge in Iowa from insurgent Bernie Sanders in the first of the state-by-state battles to pick party candidates fo