A hijab ban doesn't have a snowball's chance in hell in federal court, but might have roughly a snowball's chance in hell in state and local courts depending on where in the country it is. A hijab mandate doesn't have a snowball's chance in hell in any federal, state, or local court, even in the handful of Detroit suburbs that are the only places in American that might conceivably pass them.
As long as it is for reasons of modesty not tied to a religious stricture per se,
and perhaps if men were subject to the same requirement, it might just fly. Too big "ifs" I understand. The most analogous example where there legal activity is extant is going topless in public. From Wiki:
"In the United States, states have primary jurisdiction in matters of public morality. The topfreedom movement has claimed success in a few instances in persuading some state and federal courts to overturn some state laws on the basis of sex discrimination or equal protection, arguing that a woman should be free to expose her chest in any context in which a man can expose his. Other successful cases have been on the basis of freedom of expression in protest, or simply that exposure of breasts is not indecent (or similar terminology).
'Laws and ordinances barring female toplessness are being challenged in federal courts around the nation. Each lawsuit, if it prevails at the appellate level, will legalize topfreedom in the following U.S. circuit courts of appeals (from west to east): 9 (California), 8 (Missouri) and 1 (Maryland). A federal lawsuit in the 7th Circuit (Illinois), was lost at the appellate level and the petition for review by the U.S. Supreme Court was denied. A preliminary injunction in a federal lawsuit in the 10th Circuit (Colorado), was won at the appellate level. In September 2019, after spending over $300,000, Fort Collins decided to stop defending their ordinance and repeal it. That effectively gave females of all ages the right to go topless wherever males can in the jurisdiction of the 10th Circuit (Wyoming, Utah, Colorado, New Mexico, Kansas and Oklahoma states as well as all counties and cities therein).[94]"
In reality, a state law would be passed overriding such a local ordinance if Hamtramack et al decided to go there long before it got to higher courts. Otherwise, women might get arrested while driving
when black uncovered through the town.