Some senators worry that more casual dress might breed disrespect for Congress. Others argue that the harshest critics have already debased the institution, even in business attire.
Senator Chuck Schumer, the majority leader, will no longer enforce the informal dress code for the chamber, which for decades has dictated that members wear business attire.
When the French education minister declared that the abayas favored by some Muslim women “can no longer be worn in schools,” he stoked a fierce debate over the country’s secular ideals.