Joint analysis from the Urban-Brookings Tax Policy Center and Committee for a Responsible Federal Budget shows growth in obligations to Social Security, Medicare and payments on the country’s debt, which is approaching $20 trillion by some estimates, will grow faster than the economy can generate tax revenue over the next decade.

Presuming they were to make good on campaign promises, neither candidate will change the overall composition of the federal budget, leaving both potential administrations little flexibility to direct spending to defense, infrastructure, education, or other basic government functions, say analysts from the two think tanks.

Each campaign has proposed modest new spending initiatives. “Rather than painting their own ambitious agenda for the future, both candidates have implicitly endorsed and prioritized a preordained path,” say the analysts.

By not addressing the structural shortcomings of Social Security and Medicare, the candidates have effectively endorsed status quo policies that will continue to grow the long-term national debt.

According to the think tanks, tax revenue is expected to rise $850 billion annually by 2026 because of economic and population growth. Today, revenue accounts fro 17.8 percent of GDP; by 2026 it is expected to account for 18.5 percent.

But commitments to Social Security, Medicare and debt obligations will grow more quickly — spending on entitlements and debt is expected to be $1.28 trillion more in 2026 relative to 2016.

The analysts say that means 150 percent of the new revenue collected a decade from now will be needed to cover the growth in entitlement and debt obligations.

Trump vs. Clinton

Trump’s proposed tax cuts would explode deficits, the analysts say, and slow revenue growth to only $120 billion between now and 2026, or one-seventh of the revenue growth predicted under current law.

Trump would keep spending even, but because of his planned tax cuts, spending obligations would be 10 times more than revenue brought in.

Under Clinton’s proposals, both revenue and spending would rise faster than expected under current law.

New taxes on high earners would create another $175 billion in revenue relative to current law. But her plans to invest more on education, paid family leave and other social initiatives would add another $160 billion to the $1.28 trillion in spending for 2026 under current law.

Urban-Brookings and the Committee for a Responsible Federal Budget note that their modeling of the Clinton campaign’s pledges do not account for the expanded Social Security benefits for widows and the poor referenced in the final debate.

Under current law, there is about $32 billion projected to be available in 2026 after obligations to Social Security, health care and the federal debt are paid.

Social Security will cost $418 billion, health care $491 billion, and debt servicing $340 billion. Under Clinton, $184 billion would be available for other programs, thanks to tax increases, and under Trump, zero dollars would be available to fund other programs.

The report’s bottom line is that absent changes to how entitlements are paid and funded, the next administration will have little, and in some cases, no resources to address defense, infrastructure and education needs.

“If the next president tolerates the long-term consequences of significantly rising debt and accepts all commitments ordained from the past, he or she will be left with almost no ability to do anything new, much less respond to an unexpected economic, environmental, or defense challenge,” the report says.

“Other policy goals (universal prekindergarten, leaner government, or lower taxes) will be much harder to realize if there is no room in the budget left for them,” the analysts add.

The “excesses” of the past put the next president in danger of being a lame duck from the start of the next administration, the report concludes. Without reforms to spending and tax policies, rising entitlement and debt costs will increasingly challenge the country.

“Such a path threatens the nation’s future prosperity,” the report says.