When campaigning for reelection last year, Rep. Young Kim told voters she was working to fully repeal the cap on SALT.

Kim wasn’t referring to the top of a shaker for a condiment used to flavor food.

Rather, it’s a limit on the amount of state and local taxes (SALT) taxpayers can deduct when filing their federal taxes. The idea is to offset some of the money taxpayers have already contributed to local and state taxes when figuring out how much to pay the federal government.

Prior to 2017, there was no limit to SALT deductions, which generally benefit taxpayers in high-tax states —  including California, New Jersey and New York — and wealthier people.

But a 2017 Republican-led tax law capped those deductions at just $10,000, meaning many taxpayers from those states have had to pay significantly more.

Lawmakers from those states on either side of the aisle have since railed against the cap, proposing it be lifted significantly or even eliminated altogether.

It’s become a particular sticking point for President Donald Trump and House Speaker Mike Johnson, R-Louisiana, as they struggle with getting a massive tax breaks and spending cuts bill through the House.

And it could very well derail the entire 1,116-page bill.

The bill proposes upping the cap to $30,000 and extending the sunset permanently. Now, the cap is set to expire at the end of the year.

But that figure is still too low for Kim, R-Anaheim Hills, and a band of other SALT state Republicans. They have threatened to withhold their support of the “big, beautiful bill” unless there are significant changes to the proposed threshold.

“I’ve become one of the saltiest members of Congress,” Kim recently quipped at an event.

What SALT means for California

In 2017, about 31% of households used the SALT deduction on their taxes, according to a congressional analysis. But that decreased to just 9% by 2022, the analysis found.

Breaking that out more, 20% of taxpayers in California’s 40th Congressional District — represented by Kim, it covers eastern Orange County and parts of Riverside and San Bernardino counties — claimed SALT deductions in 2017; only 7.5% did in 2022, according to data from the National Association of Realtors.

For California’s 30th Congressional District, covering Burbank, Glendale and West Hollywood in Los Angeles County, 40.8% of taxpayers claimed SALT deductions in 2017, and 20.3% did so in 2022.

In California’s 32nd Congressional District — this one spans Los Angeles and Ventura counties and includes Malibu and Hidden Hills — 30.4% of taxpayers in 2017 claimed SALT deductions; by 2022, that was 12.6%.

Realtors also note that the current $10,000 cap is not adjusted for inflation, meaning “more current and prospective homeowners will be hurt by this limit each year,” according to the National Association of Realtors.

“This is double taxation and punishes states like California that reduce the burden on the federal government by investing their state resources into public services,” said Rep. Judy Chu, D-Pasadena, who sits on both the Budget and Ways and Means committees.

Chu blamed Republicans for implementing the SALT cap in the first place “because they wanted to punish Californians by forcing us to pay the price tag for their huge tax cut for the rich.”

“Now, Republicans are proposing to undo only part of the damage, still leaving Californians to pay the price of an even bigger tax giveaway to the ultra-wealthy while they cut benefits for everyone else,” said Chu, who has proposed fully repealing the cap.

No Democrats voted for the 2017 tax bill, and 12 Republicans also opposed it at the time. All but one of those GOP holdouts represented districts in California, New Jersey or New York. (Kim was not yet in Congress.)

Since 2017, Southern California lawmakers on both sides of the aisle — including former Reps. Mike Garcia, R-Santa Clarita, and Katie Porter, D-Irvine — have attempted to repeal or change the cap.

Even Trump, in the middle of the 2024 election, suggested scrapping the cap altogether.

But on Friday, he urged Republicans to support the provisions in the massive tax breaks and spending cuts bill, which has revived the SALT fight — and is, for now, on ice.

The bill stalled in the Budget Committee on Friday morning after a group of conservatives declined to advance it. Work is expected to continue over the weekend.