Yesterday, New York City’s new mayor Zohran Mamdani proposed raising property taxes in the city by nearly 10 percent — if he can’t persuade New York Governor Kathy Hochul to raise income taxes on the wealthy. She’s been reluctant.

In California, meanwhile, Google co-founder Sergei Brin along with former Google CEO Eric Schmidt and other billionaires are financing several voter initiatives to limit the creation of a new billionaire tax in California. California Governor Gavin Newsom is also against it.

Why are the governors of the most progressive and richest states in America so unenthusiastic about raising taxes on the wealthiest of the wealthy? The kindest answer is they’re worried that the rich will abandon their states. (The unkinder is that they’re in the pockets of said rich.)

Governors Hochul and Newsom: Don’t worry about raising taxes on the rich. True, a few rich people may abandon New York or California if taxes on them are raised, but evidence suggests the vast majority will stay put.

When billionaire New York mayor Mike Bloomberg faced a budget deficit in his first term, he raised property taxes by 18.5 percent. Rich New Yorkers threatened to leave. Most did not.

A graph from the “Citizens Budget Commission” (financed by rich New Yorkers) purports to show New York’s “shrinking share” of the nation’s millionaires — from 12.7 percent in 2010 to 8.7 in 2022 — as evidence New Yorkers are fleeing high taxes.

But that “shrinking share” isn’t due to New Yorkers fleeing; it’s because a growing number of millionaires are being hatched in Texas, Florida, and California.