The topic drew more than 300 replies, making it one of the most popular issues on the site over the past week. Explanations included Mr. Paul’s pro-life stance on abortion and remarks that women do not value liberty as much as men and that female voters do not find Mr. Paul as physically attractive as other candidates.

Susan J. Carroll, senior scholar at the Center for American Women and Politics at Rutgers University, said the explanation is probably no more complex than Mr. Paul’s limited-government views. She said those can alienate women who are more likely than men to be care providers, and who count on government assistance in those roles.

“The one thing that does divide women and men in the general electorate is their views on the role of government, with men being much more likely to want to cut back on government than women are,” she said.