The Santa Monica Rent Control Charter Amendment (Charter Amendment) empowered the Santa Monica Rent Control Board (Board) (defendant) to set and regulate maximum rents in the local housing market. Two tenants brought an administrative complaint under the Charter Amendment alleging that McHugh (plaintiff), their landlord, overcharged them for rent. The Board held hearings and determined McHugh overcharged the two tenants and awarded them restitution of excess rent. McHugh filed a petition for a writ of mandamus in trial court seeking to set aside the Board’s decision. McHugh argued the Board’s administrative adjudication of excess rents violated the judicial powers clause of the California Constitution. The trial court found in McHugh’s favor and declared the Charter Amendment invalid because it allowed the Board to exercise judicial powers in violation of Article VI, Section 1, of the California Constitution. The Board appealed.