President Trump’s proposal to reduce Social Security payroll taxes to stimulate the economy in an election year is a colossally bad idea. No doubt, the president is worried about an economic downturn as the coronavirus epidemic intensifies — and the potential impact on his re-election campaign. But that is no reason to interfere with Social Security’s finances, especially at a time when the program faces future fiscal challenges.

On Tuesday, the president tweeted that it would “great” for the “middle class” and the “USA” to temporarily cut payroll taxes — which means reducing the revenue flowing into Social Security. In fact, it would be anything but great for the millions of working people who pay into the program so that they can collect their earned benefits upon retirement, disability, or the death of a spouse.

Today, more than 40 percent of seniors rely on Social Security for all or most of their income. Economic forecasts tell us that tomorrow’s retirees will rely on their Social Security benefits even more than today’s seniors do. How many would willingly trade their future financial security for a few dollars in payroll tax cuts?

If the president wants to use Social Security to stimulate the economy, why not boost benefits — instead of cutting payroll contributions? Social Security already provides more than $1.6 trillion in economic stimulus every year — as beneficiaries spend their benefit checks in their communities. Increasing benefits would provide even greater economic stimulus.

There is legislation in Congress to expand benefits by making millionaires pay their fair share into Social Security, which we and our allies in Congress advocate. That is a much better way to put extra money into the economy without endangering working people’s future financial security through a payroll tax reduction.

This is not the first time that a president has proposed temporarily reducing the payroll tax. When President Obama pushed a payroll tax cut through Congress during the thick of the Great Recession, we opposed that, too. Lawmakers temporarily reduced payroll taxes but backfilled the lost Social Security funding with general federal revenue.

That was better than depriving the program of much-needed funding, but also undermined the fundamental nature of Social Security: that it is an earned benefit fully financed by workers’ contributions, knowing that they can collect benefits when it’s their turn.

The “earned benefit” nature of the program — purposely built into Social Security from the very beginning by President Franklin D. Roosevelt — has helped protect it from assault by fiscal hawks for more than eighty years. FDR famously declared that, because working people contribute directly to their own retirement benefits, “No damn politician can ever scrap my Social Security program.” So far, he has been proven right.

President Trump most likely did not think through his proposal before tweeting it out, and the current Congress is unlikely to comply. But if lawmakers were to temporarily cut payroll taxes, the perils would be the same as during the Obama administration. Reducing FICA contributions without compensating Social Security from general revenue would be reckless, given the fact that the program needs more, not less, revenue to remain financially healthy. But plugging any funding gap using general revenues would again undercut the fundamental nature of Social Security. It’s a lose-lose proposition that is best avoided altogether.

Meanwhile, if the president and his party truly wanted to provide tax relief to the working and middle classes, they could have targeted the 2017 Trump/GOP tax cuts toward them. Instead, more than 80 percent of the benefits from the tax cuts went to the wealthy and large, profitable corporations — who, with minor exceptions, did not raise worker pay but feathered their own nests with stock buybacks and CEO bonuses. Building an economy for the American people means strengthening Social Security — which rightly has been called the foundation of the middle class. The president should not propose measures that will weaken that foundation for his own political gain.

Max Richtman is president and CEO of the National Committee to Preserve Social Security and Medicare, a membership organization that promotes the financial security, health and well being of current and future generations of maturing Americans. He also chairs the board of the National Committee’s Political Action Committee, a PAC that endorses candidates for federal office.