I live in Colorado.
Your numbers are wrong. Proposition 69 proposes a flat, 10% tax on all income, with essentially no exemptions except for some portion of retirement income. The cost to your hypothetical household making $50,000 / year would be $5,000.
Sold your house and made a $200,000 profit? Cough up $20,000.
Inherited $300,000 from a relative? $30,000 to the state.
Self-employed and making $150,000 / year? Your cost is $15,000.
They try to hide this fact by structuring the 10% increase as a 3.33% payroll tax increase “paid by employees”, and a 6.67% increase “paid by the employer”. Aside from the fact that many people are self-employed and/or get substantial income from non-payroll sources, and thus will be directly responsible for the entire 10% increase, it is also ludicrous and misleading to pretend that businesses will just absorb this cost, especially for higher-paying jobs for which it likely exceeds what the business is currently paying to offer health insurance.
This will make it very uneconomical to operate businesses in Colorado that provide well-paying jobs, and it will drive away talented young people who do not presently spend anything close to 10% of their income on healthcare.
I do believe there is a cap on the maximum income subject to the tax, but it is ludicrously high, something like $450,000 / year.
Personally, I am an independent contractor, and my income has ranged from $50,000 to $170,000 over the past few years. I spend only $3,600 / year on health insurance and rarely use any health services. I also don’t expect to live in Colorado for the rest of my life. If this passes, it will be absolute bullshit for me to have to pay an extra $17,000 into a socialized medicine program that I likely will never even benefit from, and I’ll probably leave the state.
The exodus of talented, highly-paid professionals will tank the economy and the entire program will become insolvent once they run out of productive taxpayers to foot the bill.