Wealth Tax Backfires? Cuban Sounds Alarm

Stacks of U.S. hundred-dollar bills — Photo: FOTO SALE / Shutterstock

Billionaire Mark Cuban just told a sitting Democrat congressman that California’s new wealth tax plan is built on ideology, not common sense.

Story Snapshot

Mark Cuban publicly criticized Rep. Ro Khanna for backing California’s billionaire tax, telling him “Ideology is not a strategy.”
The measure would impose a one-time 5% tax on residents worth more than $1 billion, applied retroactively to January 2026.
Supporters say the tax could raise close to $100 billion for programs like Medi-Cal.
Cuban warns the tax could push founders, investors, and capital out of California for good.
Even some Democrats, including Gov. Gavin Newsom, are keeping their distance from the plan.

Cuban Calls Out Khanna’s Wealth Tax Push

Mark Cuban went after Representative Ro Khanna directly over the California billionaire tax. Cuban told him flatly, “Ideology is not a strategy,” pushing back on Khanna’s support for the plan. Cuban isn’t a random critic. He’s a billionaire entrepreneur who understands how business capital actually works, and he says this tax ignores that reality entirely.

What California’s Billionaire Tax Would Actually Do

The proposal, headed to California voters this November, would slap a one-time 5% tax on residents worth over $1 billion. It applies to stocks, businesses, art, and intellectual property, though real estate and retirement accounts are excluded. The tax would hit anyone who lived in California as of January 1, 2026, and it already qualified for the ballot after organizers gathered enough signatures.

Cuban warned this kind of tax forces wealthy business owners to keep huge cash reserves just to cover a bill, instead of investing that money into companies and jobs. He argued the plan could drive founders straight out of California, taking their startups and their money with them.

Democrats Split as Newsom Keeps His Distance

Khanna, who represents Silicon Valley, calls the tax “modest” and says it will fund healthcare for working families, including Medi-Cal. Backers claim it could recover about $90 billion in Medicaid money they say Republicans stripped from the state budget. But Governor Newsom has stayed cautious, worried the plan could scare off wealthy taxpayers and destabilize state finances at the worst possible time.

Even inside Khanna’s own political base, the reaction has been rocky. Tech industry supporters who once backed him are now reportedly reconsidering their support because of his stance on the wealth tax. That kind of backlash from his own Silicon Valley donors shows just how divisive this idea really is, even among people who usually side with Democrats on economic policy.

The Economic Evidence on Wealthy Flight

Research on wealth taxes elsewhere backs up some of Cuban’s worries. A Hoover Institution analysis found real out-migration effects tied to tax rate hikes, with departures from high-tax states accelerating over time. Scandinavian data tells a similar story. A one-point increase in the top wealth tax rate shrank the population of wealthy taxpayers, and businesses run by those who left often saw real economic damage.

"If this passes, only idiot startup founders stay in Cali."

Mark Cuban is sounding the alarm as California voters prepare to decide on a one-time 5% wealth tax targeting billionaires.

His warning comes as IRS data show taxpayers are already leaving California by the thousands.… pic.twitter.com/Rswu8TnAG8

— FOX Business (@FoxBusiness) August 17, 2026

State tax analysts warn the fallout could hit California’s own budget. One estimate projects the state could lose between $3.5 billion and $4.5 billion in yearly tax revenue if enough billionaires simply move away before the tax takes effect. That’s the exact outcome Cuban is pointing to: chase away the people paying the biggest tax bills, and the state ends up worse off, not better.

Why This Fight Matters Beyond California

This fight is bigger than one ballot measure. It’s a preview of what happens when progressive politicians chase headlines instead of results. Conservatives have warned for years that punishing success drives job creators away and shrinks the tax base that funds real services. Cuban, a billionaire himself, just said the quiet part out loud: good intentions don’t pay the bills, and neither does ideology.