https://itep.org/whopays-7th-edition/#income-taxes

This report identifies the most regressive state and local tax systems and the policy choices that drive that outcome. Many of the most upside-down tax systems have another trait in common: they are frequently hailed as “low tax” states, often with an emphasis on their lack of an income tax. But this raises the question: “low tax” for whom?

This study finds that very few states achieve low tax rates across the board for all income groups, and those that do usually rely heavily on energy or tourism sectors that cannot realistically be replicated elsewhere. Alaska is the only state that ranks among the bottom 10 lowest-tax states for all seven income groups included in the study. New Hampshire and North Dakota are among the lowest-tax states for six of their seven income groups. Nevada, South Dakota, and Wyoming have low taxes for five of their income groups.

The absence of an income tax, or low overall tax revenue collections, are often used as shorthand for classifying a state as “low tax.” These two measures are, in fact, reliable indicators that taxes will be low for the highest-income earners, but they tell us next to nothing about the tax level being charged to low-income families.

Florida, Tennessee, Texas, and Washington all forgo broad-based personal income taxation and have low taxes on the rich, yet they are among the highest-tax states in the country for poor families. These states are indicative of a broader pattern. Using the data in this report, we find a modest negative correlation between tax rates charged to the lowest and highest income groups. In other words, if a state has low taxes for its highest-income earners, it is more likely to have high taxes for its lowest-income residents.

Similarly, we find that the overall level of tax revenue collected in a state has almost zero correlation with the tax rate charged to that state’s lowest-income families. Put another way, states that collect comparatively little tax revenue tend to levy tax rates on poor families that are roughly on par with those charged in other states. And, as a group, states collecting higher amounts of revenue do not do so with above-average tax rates on the poor.

For high-income families, on the other hand, overall revenues are highly correlated with their own personal tax bills. This suggests that high-income families receive a financial windfall when a state chooses to collect a low level of tax revenue overall, though that windfall comes at the cost of fewer or lower-quality public services.

Here you go.

Also the corresponding graphic to make it clearer:

Income taxes get all the attention but they aren't the only taxes.

I don't know about the 600k figure specifically though.

It’s an odd argument, but I think it comes down to sales tax and property tax. Property tax is high in texas, and sales tax is 7% (not the highest in the nation, but high, and local sales tax can also run 1-2%). I think the theory is that you only pay so much sales tax in goods for one person, so it balances out california’s higher property taxes.