It Takes a Candidate serves as the first systematic, nationwide empirical account of the manner in which gender affects political ambition. Based on data from the Citizen Political Ambition Study, a national survey conducted on almost 3,800 'potential candidates', we find that women, even in the highest tiers of professional accomplishment, are substantially less likely than men to demonstrate ambition to seek elected office. Women are less likely than men to be recruited to run for office. They are less likely than men to think they are 'qualified' to run for office. And they are less likely than men to express a willingness to run for office in the future. This gender gap in political ambition persists across generations. Despite cultural evolution and society's changing attitudes toward women in politics, running for public office remains a much less attractive and feasible endeavor for women than men.