In a nation long shaped by the tension between sovereign authority and legislative constraint, a federal appeals court in Boston has reaffirmed that the power to tax belongs to Congress alone. The court refused to revive a $100,000 fee on H-1B visas that the Trump administration had imposed by proclamation, finding no lawful foundation for the charge. The ruling leaves intact a program that has for decades served as a bridge between American industry and global talent, while reminding the executive branch that ambition, however sincere, must still answer to constitutional limits.