It hardly seems fair but Mississippi puts a limit on this deduction. The limit is the same limit as the federal government which is $10,000.
State income taxes, or any other taxes allowed for federal purposes in lieu of state income tax, including taxes withheld on Mississippi gaming winnings, are not deductible on your itemized deductions schedule.
From the Missippi instructions:
State income taxes paid or any other taxes allowed in lieu of federal purposes including withholding taxes on Mississippi gaming winnings, are not deductible as an itemized deduction.
Remember, based on Tax Cuts and Jobs Act, there is a $10,000 limitation on this deduction.
Full Mississippi instructions on page 15:
https://www.dor.ms.gov/Forms/80100188.pdf
