HEMPSTEAD, N.Y. — A far more aggressive President Barack Obama showed up for his second debate with Mitt Romney on Tuesday, and at moments their town-hall-style engagement felt more like a shouting match than a presidential debate.

The two men insistently challenged each other on the facts, talked over each other and stalked each other across the stage.

Moderator Candy Crowley of CNN faced a difficult task all night in trying to keep to the intended format as both candidates insisted on answering nearly every charge from his opponent, regardless of the time limits.