New Delhi, Nov. 3 -- Election Day is upon us, and so are wealth-related proposals on some state ballots.

By several measures, the ultrawealthy-particularly those minted from the AI boom and yearslong bull-market run-have dwindling liquidity at the same time calls to tax the rich amplify. Inevitably, some will have to decide how to pony up more cash to the taxman if the handful of measures are successful.

The states of concern on Tuesday are California, Colorado and Washington, where voters will decide whether millionaires and billionaires should pay more. Pass or fail, they are unlikely to be the last measures targeting the richest Americans amid growing income inequality.

"Wealth tax ideas come in waves, and it's experiencing some kin...