A thick wall of tear gas crept closer to the wall of moms in yellow shirts chanting, “Don’t shoot your mother,” as they faced off with federal agents during another night of nonstop protests. As the gas enveloped the group late Tuesday, some began to cough. One mom ripped off her goggles in frustration — they didn’t seal around her eyes and the burning gas had seeped in. She rubbed her face and let out a groan, but she didn’t leave. Neither did hundreds of other self-identified moms who showed up at the latest round of protests to stand, arms linked, between armed federal agents and demonstrators. In front of the federal courthouse, federal agents in tactical gear used batons to push back the moms in bike helmets. Dozens were tear-gassed. Some were hit with less-lethal bullets fired into the crowd.