The Supreme Court is taking up a dispute over how a state, such as Maryland, might tax the income its residents earn in another state.
This week the high court agreed to hear an appeal from officials in Maryland who want to overturn a lower court ruling which labeled the state's tax law unconstitutional.
Right now, Maryland law allows residents to deduct income tax paid to other states from their state tax. However, it does not apply that deduction when it comes to local so-called ``piggyback taxes'' which the state collects for county and city governments.
Last year, the Maryland Court of Appeals ruled the tax violates the state constitution's Commerce Clause and discourages Maryland residents from earning money outside the state.
Maryland state Attorney General and gubernatorial candidate Douglas Gansler says the state has authority to tax all income of its residents.