Yes.
You will include nontaxable income like social security income in the calculation for the sales tax deduction. See the following from the IRS Sales Tax Deduction Calculator:
Your income is the amount shown on your Form 1040, "Adjusted Gross Income" line, plus any nontaxable items, such as the following:
- Tax-exempt interest
- Veterans' benefits
- Nontaxable combat pay
- Workers' compensation
- Nontaxable part of social security and railroad retirement benefits
- Nontaxable part of IRA, pension, or annuity distributions. Do not include rollovers
- Public assistance payments
- And any other nontaxable items
