In the last several decades pornography in the U.S. has become more mainstream, more accessible, more phallocentric and more degrading to women. Further, consumption of pornography remains a major difference in the sexual experiences of men and women. Yet research has not addressed how opposition to pornography has changed over the this period, despite shifts in the accessibility and visibility of pornography as well as new cultural and legal issues presented by the advent of Internet pornography. We examine gender differences in opposition to pornography from 1975 to 2012, measured by support for legal censorship of pornography in the General Social Survey. Results show that both men's and women's opposition to pornography have decreased significantly over the past 40 years, suggesting a cultural shift toward "pornographication" affecting attitudes. However, women remain more opposed to pornography than men, and men's opposition has declined faster, so the gender gap in opposition to pornography has widened, indicating further divergence of men's and women's sexual attitudes over time. This is consistent with the increasingly normative nature of pornography consumption for men, increases over time in men's actual consumption of pornography, and its increasingly degrading depiction of women.