Jared Walczak of the Tax Foundation provides reasons for skepticism about state efforts to preserve the deduction for state and local taxes.

[T]he two main approaches that have emerged as possibilities are (1) allowing individuals to make contributions in lieu of taxes to the state treasury or a specific state fund to enable taking the full amount under the charitable deduction; and (2) swapping individual income tax liability with tax-deductible employer-side payroll taxes. . . .
States pursuing such tax dodging strategies, however, face significant obstacles. To be deductible, charitable contributions must have a genuinely charitable aspect, and cannot primarily benefit the contributor or involve a quid pro quo. Payments which function as taxes may be classified as taxes even if states choose to call them something else. The viability of a payroll tax approach depends in large part on the complete absence of wage stickiness, and if paired with a graduated-rate income tax, may be unimplementable. These ideas, however creative, have dim prospects of success.