Clinton, Sanders go on the attack in fiercely combative debate

By Luciana Lopez and Jonathan Allen NEW YORK (Reuters) - Democratic front-runner Hillary Clinton and rival Bernie Sanders challenged each other's judgment and experience in a fiercely combative U.S. presidential debate ahead of Tuesday's crucial nominating contest in New York. Clinton and Sanders attacked each other over Wall Street, gun control and other issues on Thursday in a series of exchanges that laid bare the mounting pressures on them both but seemed unlikely to change the dynamics of t