Payroll taxes already exist in several states:

https://en.wikipedia.org/wiki/Payroll_tax#United_States

and will continue to exist and be perfectly legal unless Congress passes a law against them.

They are special taxes used to fund employment-related things. Why do you think they could be increased significantly and used to fund general spending, replacing income taxes?

Nevermind, it seems that states are actually trying this work-around (at least NY has introduced something in that direction):

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3089423

The Games They Will Play: Tax Games, Roadblocks, and Glitches Under the 2017 Tax Legislation

III. STATE GOVERNMENT RESPONSES TO THE SALT DEDUCTION CAP

B. Increased Use of Payroll Taxes