Late Friday, Gov. Andrew Cuomo of New York sent a radical bill to cap property taxes to the State Senate. It would devastate school districts in the state. The bill, which exempts New York City, was passed by the Senate on Monday.

But Democrats in the Assembly are rightly startled by a provision that would require a 60 percent majority vote for local property tax increases that exceed 2 percent. That would give people who oppose school spending more voting power than people who support it. It would also leave struggling school districts with no increase if voters rejected an increase twice within a given year.

The bill would also do away with the traditional school budget vote and require districts to simply ask voters to support a tax increase. That would make new school financing virtually impossible in many of the poorest communities. Unlike New Jersey’s tax cap, this one does not have exemptions for health care, pensions, debt service or increased enrollment. Mr. Cuomo has said he wants to change state law to lift these onerous and costly requirements for local districts. That should come first.

The governor’s motives for bringing out this bill now are unclear. Does he want political points for introducing a tough bill that can never go anywhere? If so, that is one of the oldest ploys in Albany and certainly at odds with Mr. Cuomo’s promise of a new New York.

Does he want to force Democrats in the Assembly to approve the bill after he and the Senate have given their approval. The Assembly speaker, Sheldon Silver, who can stall or block anything if he wants, should not be talking about compromise, as he has been. But, rather, he should block any Senate bill along these lines.

The entire charade fails to focus on the real hazards tucked in the 74-page bill. A property tax cap, by any standard, is a blunt instrument. It mainly squeezes poorer districts where schools lose teachers or advanced programs because voters reject a tax increase. Wealthier districts more often vote for property-tax increases to pay for better schools or other services, thus widening the gap between schools in poorer or richer areas.

Mr. Cuomo’s tax cap effort is a bad bill that promotes a bad idea. People do need property-tax relief but not another state law that makes matters worse.