Iowa gives Trump's unorthodox campaign its first test

By John Whitesides DES MOINES, Iowa (Reuters) - Republican front-runner Donald Trump puts his precedent-shattering campaign to the test on Monday when Iowa voters begin the nationwide process of choosing a new U.S. president, as polls show a tight battle with Ted Cruz that could hinge on turnout and a large bloc of undecided voters. On the Democratic side, front-runner Hillary Clinton also faces a stiff challenge in Iowa from insurgent Bernie Sanders in the first contest in the state-by-state ba