They packed the Small Business Committee hearing room and offered detailed testimony on the benefits of unionization and the harm such a law would cause.
Demonstrators protesting the national wave of wage and safety cuts and anti-union assaults, were led by the West Virginia AFL-CIO and joined by national labor leaders.
"In reality, it would rob poor and struggling students of the resources, supports, and funding they need to succeed."
The FMLA was intended "to balance the demands of the workplace with the needs of families."
The pioneering Retail Workers Bill of Rights will give an estimated 40,000 hourly workers greater stability in their schedules and hours.
Delegates adopted a multi-point action platform for coming years to battle what President Gerard called "shrewd, greedy and powerful" forces out to destroy workers.
"We cannot afford to add to driver fatigue by rolling back hours-of-service regulations, which were carefully crafted over the course of more than two decades."
"The industry employing her is in receipt of the working energy of a human being at less than its cost, and to that extent is parasitic."
The Senate tried to raise the nation's minimum wage to $10.10 per hour by 2016. But its Democratic sponsors needed 60 votes to start debate, and got six fewer than that.
The target will be schemes to cut postal services, end Saturday pickup and delivery, and fire or let go by attrition hundreds of thousands of workers.