The House Democrats’ plan to expand the federal deduction for state and local taxes (SALT) in their reconciliation bill surely has Republicans rubbing their hands with glee. As Sen. Bernie Sanders (I-Vt.) has pointed out, this would be a massive, undeserved tax break for the richest Americans — and something Democrats will wholly own since Republicans passed a $10,000 cap on the deduction as part of their 2017 tax bill.

So long as the GOP are attacking giveaways to the rich, they should also embrace eliminating other unjustified tax breaks. Doing so would be a political winner and could save the government tens of billions of dollars each year.

The SALT deduction is one of hundreds of special tax breaks that individuals and corporations use each year to substantially lower their tax bills. They are particularly fond of deductions or exclusions because of the relatively high marginal tax rates they face. Married taxpayers earning $628,301 in taxable income or more pay 37 percent of that amount to the federal government. Every dollar that they can exclude or deduct, therefore, saves them 37 cents in taxes. That’s a superb, risk-free rate of return.

These tax breaks are costly. Restoring the full SALT deduction, as House Democrats now propose, would cost the federal government nearly $89 billion for one year. The Joint Committee on Taxation estimates that 71 percent of that would go to households making more than $500,000 a year, giving them nearly $64 billion a year in tax relief. No wonder Sanders says this is “beyond unacceptable.”

Once one opposes this tax break, though, it’s hard to draw the line and support many of the others America’s rich also get. Smart Republicans should seize this opportunity and start agitating to repeal other provisions, too.

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The Joint Committee on Taxation reports that America’s tax breaks — called “tax expenditures” by tax experts — results in the federal government forgoing nearly $1.7 trillion in revenue each year. Nearly $1.2 trillion of this amount goes to households earning at least $200,000 a year. While data are not broken down for households above that amount, data from the Internal Revenue Service for the 2018 tax year show that households earning more than $500,000 a year report roughly 56 percent of all adjusted gross income in this group. In other words, households earning more than $500,000 a year likely benefit from about $672 billion each year from tax expenditures.

Many of these expenditures are difficult to justify for the well-to-do. The mortgage interest deduction, for example, is intended to help people afford to buy a home. Why do America’s richest need such help?

The same is true for the exclusion of health insurance premiums from federal income and payroll taxes. It’s one thing not to tax such payments for middle-class Americans, since health insurance is so expensive. They might not be able to otherwise afford comprehensive care. The rich have no such barrier. Why should they not pay taxes on income used for premiums?

Then there’s the measure exempting from taxes the first $500,000 of capital gains for the sale of one’s principal residence. Do Wall Street billionaires need to save yet another $100,000 or so on their taxes when they sell their mansions?

Other tax breaks may have more justification but are still questionable for the super rich. The government forgoes roughly $293 billion in revenue each year by excluding contributions for retirement plans such as company pension funds, 401(k) accounts and IRAs. This encourages people to save for retirement, which is a worthy goal. But people earning massive amounts of money each year don’t need incentives to save for retirement; they have plenty of money to devote to this goal while maintaining a very comfortable standard of living.

Deductions for charitable contributions are another gray zone. Should Bill Gates get to deduct billions of dollars for contributions of Microsoft stock to his eponymous foundation, which then advances his ideological goals through its own tax-protected status?

Taking aim at these and other similar provisions would raise tens of billions of dollars each year without raising marginal tax rates. That would go a long way toward reducing our massive annual budget deficit. Imagine a GOP budget-balancing package that combined repealing unnecessary tax breaks for the rich with full taxation of capital gains from big university and foundation endowments and means-tested entitlements while also ensuring that rich retirees no longer receive Social Security or Medicare subsidies they don’t need. This could cut the deficit by hundreds of billions of dollars each year without costing the average American a penny.

A politically successful future Republican Party will have to be an alliance between economic conservatives and blue-collar populists. Backing the elimination of the unfair tax breaks benefiting the nation’s elites might be the cement that glues the coalition together.