The U.S. economy is delivering some of the best employment and income gains of the past 40 years, boosting workers in a way that recalls the boom years of the 1980s and 1990s.

But while the gains may help Hillary Clinton rebuff Donald Trump’s frequent attacks on the state of the nation and the Obama administration’s record, she would face a series of minefields if she wins the White House. As would Trump, if he pulls off a victory.

Economists say there is a one in five chance of recession next year. The Federal Reserve is on a march toward raising interest rates. And threats continue to flow from abroad, including the United Kingdom’s exit from the European Union and other signs of turbulence in the global economy.

A recession – or even a decline in economic momentum – could rapidly expose the new president to criticism and change the ability of the new administration to accomplish its goals.

“When the economy goes south in the first term, it’s a treacherous situation for a president hoping for re-election,” said Nicole Hemmer, a presidential historian at the University of Virginia.

If wage and employment gains persist for the next four years, many of the concerns about worker stagnation that have dominated the national discussion could ease. If not, it could complicate the next president’s agenda as he or she faces questions about presiding over a weak economy.

The winning candidate appears certain to take office under far less economic strain than Obama did in 2009, in the thick of the Great Recession. In the past two years the economy has gained an unusual level of momentum, with sharp improvements for many Americans.

Unemployment is low, some out-of-work Americans are rejoining the labor force, and wages rocketed higher in 2015 at their fastest pace since the U.S. Census started keeping track 50 years ago.

“The recovery has been accelerating in terms of incomes,” said Robert Shapiro, an economist who worked in the Clinton White House, and who has donated to Hillary Clinton’s presidential campaign. “What we are seeing is a return to the faster pattern” of the 1980s and 1990s, he said.

Other data show jobs are being created at a better pace than any time during George W. Bush’s presidency.

The current economy is far from roaring on all measures, of course. The most notable disappointment is economic growth, which averaged about 2.2 percent a year from 2013-15 and is doing even worse this year. That’s well below the 1980s and 1990s.

“Normally after a recession ends … you see growth on average of about 5 percent” a year, said Beth Ann Bovino, the U.S. chief economist for S&P Global Ratings. “We never saw that.”

Millions of Americans in prime working age, meanwhile, have yet to start looking for work again after leaving the labor force during or after the recession. Many lower-income and middle-class families have not rebuilt the wealth they lost in the recession. And the typical U.S. household still earns less than it did in 1999, a high point.

Republican presidential nominee Donald Trump has accentuated those negatives when campaigning on the economy. Clinton has pressed a more upbeat view, praising Obama for nurturing the recovery but stressing workers still need more help from policymakers.

“We are heartened by what we see,” said Jacob Leibenluft, a senior adviser to Clinton. “It provides a good foundation to build off. But we see the remaining challenge: Many families feel anxieties and squeezes that are not imagined. They are real.”