How about paying two-thirds of your income in taxes? It could happen.

California’s combined tax burden could climb to more than 66 percent of income under a new proposal that would remove the current cap on Social Security payroll taxes.

The measure, sponsored by Senator Elizabeth Warren, would eliminate the 12.4 percent Social Security payroll tax cap for people earning more than $185,000 a year. In California, where the cost of living is the highest in the nation, many argue that income level is middle-income for a household.

If the proposal becomes law, Americans for Tax Reform estimates the top combined tax rate for California residents would reach 66.5 percent once federal income taxes, state income taxes, payroll taxes, and Medicare taxes are added together—making California the highest-taxed state in the nation under that calculation.