States’ Last-Ditch Bid to Kill Trump’s SALT Cap Eroded by Data

It was always a long-shot, but a quixotic lawsuit by four northeastern states to squelch the Trump tax law’s cap on state and local tax deductions is getting undermined by a repetitive drip of strong economic data.

New York, Connecticut, Maryland and New Jersey will get their first hearing in June on a last-gasp attempt to kill one of the most controversial provisions of the 2017 tax law. To do so, their attorneys general are relying on early-1900s news clippings and Civil War-era congressional debate over whether to even have an income tax.

The case, being heard in U.S. District ...