Having a bunch of (medicare-covered) retirees (with no school-age kids) spending their (taxable) social security income in NY / CA sounds pretty great. Much better than losing them to Florida or Arizona. Bonus if the states get to tax their estates in the end.

The fact that they are Medicare covered means the retirees will choose to retire in lower tax jurisdictions. They do not need state governments to provide healthcare.

Half of California's tax revenue comes from the top 1% [1]. Medicare retirees are almost guaranteed to not be part of that 1%. You're talking huge tax revenue losses here if the 1% do decide to leave.

[1] https://lao.ca.gov/LAOEconTax/Article/Detail/7

I think he means people who have enough money at, say, 40 years old, to pay for everything but health insurance. I can see the temptation myself, since insurance as you get into your 50s can be 2000/month or more. If NY State pays that while I wait for Medicare to kick in, hey, FIRE!

Retirees usually use Medicare.