The statue of Grief and History is pictured in front of the U.S. Capitol Dome in Washington, Oct. 16, 2013. (KEVIN LAMARQUE/REUTERS)

There is a way to prevent government shutdowns. A change in U.S. law would keep federal workers on the job and ensure that treasured sites such as the Statue of Liberty and Yosemite National Park stay open during a budget fight instead of becoming political pawns.

The idea has been around for three decades, but even after a 16-day shutdown this month that cost billions of dollars and outraged voters, it’s a tough sell in Washington.

Why? Without the risk of a shutdown, there’s no telling how long politicians might put off hard budget decisions. The United States could end up with government by autopilot.

Even those who say an anti-shutdown law could avoid that trap find it tricky to come up with a plan that’s acceptable to the factions locked in budget gridlock these days.

Nevertheless, a prominent fiscal conservative is reviving the idea as lawmakers seek a budget deal to head off the risk of another shutdown in January. Sen. Rob Portman (R-Ohio) will use his spot on the House-Senate negotiating team to push his prevention measure, said his spokeswoman Caitlin Dunn.

Portman, a former White House budget director in the George W. Bush administration, wants to goad lawmakers to finish their overdue appropriations work by cutting spending as time goes by.

If lawmakers miss their Oct. 1 deadline, agencies would stay at the previous year’s spending level for 120 days. After that, spending would drop by 1 percent every 90 days.

“It’s appealing to take the risk of shutdown off the table,” said Marc Goldwein of the Committee for a Responsible Federal Budget, a bipartisan group seeking to curb the national debt. “But it has its risks.”

Money to fund the federal government is appropriated each fiscal year, but Congress almost never finishes its regular appropriations bills on time. The usual solution is to approve “continuing resolutions,” which let agencies keep going at the current spending levels. Without spending power, they must send workers home.

Shutdowns are so disruptive that politicians rarely resort to them. This month’s was the first in 17 years. While many government operations stopped, the closing of national parks and related sites — from the museums and monuments along the Mall to the Statue of Liberty to Rocky Mountain National Park — was one of the disruptions most visible and upsetting to the public.

But trying to end the risk of a shutdown could cause new issues.

“If funding for the previous year never actually expires, their motivation to pass an appropriations bill would be lower,” Goldwein said. If lawmakers shirk their duty to adjust spending to reflect the nation’s changing needs, he said, “it would be bad for the country.”

Senate Democrats rejected the Portman plan, co-sponsored by Sen. Jon Tester (D-Mont.), by a nearly party-line vote in January. Portman is also getting resistance from conservatives who want to keep the shutdown leverage embraced by tea partyers.

Shutdowns didn’t become a political tactic until 1980, when the Carter administration took a closer look at a decades-old budget law and realized that it requires agencies to send all but the most critical workers home if funding lapses. The comptroller general recommended that Congress fix the problem back in 1981.

Lawmakers tried many times but came close just once, after the 1995-96 budget showdown. The GOP-controlled Congress, branded with most of the blame for two shutdowns, attached a prevention measure to a flood-relief bill. But the plan was anathema to Democrats — it would have kept agencies open but imposed a 2 percent budget cut.

President Bill Clinton vetoed the bill because it would have let Republicans cut spending simply by taking no action.

Depending on how they’re designed, automatic funding schemes can create incentives for either budget-cutters or defenders of the status quo to block spending bills because they prefer the default option. Richard Kogan of the liberal-leaning Center on Budget and Policy Priorities calls that “governing by paralysis.”

“It would make government less responsive than it already is,” Kogan said. “That’s got to be a bad thing.”

— Associated Press