Maryland Attorney General Brian Frosh said Thursday that he plans to sue over the tax law President Trump signed in December, joining officials in New York, New Jersey and Connecticut in planning a legal challenge.

Officials in high-tax states are arguing that the law's $10,000 cap on the state and local tax (SALT) deduction is unconstitutional. The cap is particularly harmful to residents of blue states that tend to have higher taxes.

"By eliminating the SALT deductions, Trump's tax bill will jack up taxes for more than half a million Marylanders," Frosh, a Democrat, said in a news release. "It is an attack on state sovereignty and an attempt to cripple our ability to educate our kids, protect the Chesapeake Bay, and build the infrastructure that Maryland needs to be competitive in the world economy."

A legal challenge is one of several maneuvers that blue-state politicians are considering as they try to figure out how to circumvent the cap on the SALT deduction. Politicians are also pushing for the creation of new state funds to which taxpayers can make tax-deductible charitable contributions, and are considering shifting their income-tax systems to payroll-tax systems.

Tax experts across the political spectrum predict that politicians who sue over the tax law are unlikely to win. They have said the federal government has broad authority to levy an income tax, and they have noted that the SALT deduction has long been curbed by the alternative minimum tax.