Ms. Fiorina’s comments were, all told, really no more incendiary than a bit of warm pasta salad — who hasn’t indulged in some off-the-record chitchat about the grooming habits of others now and then? But they presented her with a political problem that could haunt her throughout the campaign.

They both inform and confirm the image from her days as chief executive at Hewlett-Packard that she is tart and unpleasant. And they open the entire campaign to perceptions, however tired or unfair, that women can be dragged down the road of pettiness, perceptions that detract from the serious and pressing issues of the day.

“The fact is that some voters, including many women, find this interesting and no doubt form their character judgments on such matters,” said Bruce E. Cain, a professor of political science at the University of California, Berkeley.

“Of course, bad or old-fashioned hair can become a metaphor for being out of step and in need of change,” he added.