Congressional inaction drives LGBT rights case at Supreme Court.

A case before the Supreme Court on Tuesday could have sweeping social implications since 28 states have no express protections for LGBT employee rights. (Tom Williams/CQ Roll Call file photo)

The Supreme Court confronts a major civil rights issue Tuesday over how broadly the justices should read the word “sex” in a 55-year-old anti-discrimination law — and a key aspect is Congress’ current push to clarify that the law covers LGBT individuals…