In the long tension between federal authority and local governance, Arlington County has become a focal point for a national reckoning over sanctuary policies. A House Judiciary Committee report accuses the county of erecting institutional barriers against immigration enforcement — not merely through police policy, but through the prosecutorial discretion of its Commonwealth's Attorney. The dispute asks an ancient question in new form: when local officials believe federal consequences are unjust, do they have a duty to shield their residents from those consequences, or does that shield itself