For the first time in a decade, legislation to put teeth into the nation’s 56-year-old equal pay law appears headed for real debate, votes and passage by the Democratic-run U.S. House.

How far it gets beyond that is up to forces beyond the control of its congressional backers. Foes include congressional Republicans – who run the White House and the U.S. Senate – and, as might be expected, the corporate class, led by the Chamber of Commerce.

That prospect didn’t faze the three lawmakers and representatives of women’s groups who campaigned for the measure, the Paycheck Fairness Act, at a congressional hearing.

By giving workers more power to discuss wages, banning company retaliation, really slamming law-breakers legally and disclosing pay data in broad categories – thus shaming discriminatory employers while putting a powerful tool in workers’ hands – the advocates said the measure would help shrink the huge pay gap where working women trail working men.

And it also could be part of a package that could help cut U.S. poverty and income inequality, they testified. Other sections of that package include raising the minimum wage, enacting paid family leave and, as one new female Democrat from Michigan reminded everyone, strengthening worker rights.

Federal data show the median pay for a working woman nationwide is 80 cents for every dollar a working man in the same or similar jobs, with the same qualifications, earns. The ratios are even worse for African-American (61 cents), Latinas (53 cents) and Native American women (58 cents). The median is where half the workers are under that figure and half above.

Though witnesses didn’t say so, union women are the exception to that dismal picture. The median weekly pay for unionized working women is 92 cents per union working man’s dollar. Working union women also out-earn every other group of workers, male and female, except unionized men.