Here's your Forbes daily briefing for Monday, June 30th.

Today on Forbes, will Mamdani's proposed millionaire tax save or sink New York City?

What would be the real result of a new millionaire tax in New York City?

Bill Ackman, founder and CEO of Pershing Square Capital Management, and a Trump

and Cuomo backer, suggests the answer is that wealthy taxpayers will flee.

In a post on X, Ackman lamented Zohran Mamdani's Democratic primary win in the New York City

mayoral race by stating, quote, New York City under Mamdani is about to become much more

dangerous and economically unviable.

Ackman's Post, which has garnered more than four million views, was a direct response to

Mamdani's surprise Democratic primary win in the Big Apple.

The 33-year-old Democrat garnered 44% of the vote running on a progressive

agenda focused on making life in New York City more affordable. Funding that agenda will take money,

and Mamdani has a plan to raise revenues without tapping the middle class. In addition to bumping

up the corporate tax, Mamdani has proposed a 2% tax on what his campaign calls, quote,

the wealthiest 1% of New Yorkers, those earning above $1 million annually.

His platform estimates this so-called millionaire tax will raise $4 billion annually to help fund projects like universal free early child care,

free bus rides, and more affordable housing.

The numbers, Mamdani says, mean that the tax would impact about 34,000 households.

On his website, he says, quote,

this tiny share of the city population takes home 35% of all income earned by New York City

residents.

That same 1% he explains also benefited from a tax cut under President Trump's 2017 Tax Cuts

...