Michael Barone‘s latest column delves into the details of the president’s arguments about “equal pay” for men and women, especially the misleading statistic of women earning 77 cents of pay for every dollar men make.

This isn’t controversial stuff. As my American Enterprise Institute colleague Christina Hoff Sommers writes in the Daily Beast, the 77 cents “does not account for differences in occupations, positions, education, job tenure or hours worked per week. ”

Those factors are acknowledged in a 2012 Bureau of Labor Statistics report cited by AEI scholars Mark Perry and Andrew Biggs in the Wall Street Journal. It shows that (a) men tend to work longer hours than women, (b) men tend to take riskier jobs with premium pay, and (c) female college graduates tend to specialize in lower-paid fields than do male college graduates.

As a result, the BLS concludes, women who worked 40-hour weeks earned 88 percent of what similar men did. Single women who never married earned 96 percent of men’s earnings.

Stevenson concedes that not all the differential comes from discrimination or sexism. “Some of women’s choices come because they are disproportionately balancing the needs of work and family,” she told MSNBC.

By “disproportionately,” she presumably means that more women than men choose to stay home to care for children. “Which of these choices should we consider legitimate choices,” she asks, “and which of them should we consider things that we have a societal obligation to try to mitigate?”

This raises the specter of government bureaucrats intervening in marital decision-making, pushing more husbands to stay home with the kids. Even the Obama administration stops short of that.

The Democrats’ problem is that sex discrimination by employers was outlawed by the Equal Pay Act signed by John Kennedy in 1963 — 51 years ago. To make “the war on women” an issue and rally single women to the polls, the Obama Democrats have had to concoct new legislation putting new burdens on small employers and ginning up business, as the 2009 Lilly Ledbetter Act’s extended statute of limitations did, for their trial-lawyer contributors.

Such legislation attacks a problem very largely solved.