Once upon a time, May 1 — May Day — was a day for working-class parades in factory towns. This year, it was a day for Joe Biden, to set off on his third presidential campaign in 32 years, to make news on the stump, not in a working-class venue but in the university town of Iowa City, now the state’s Democratic stronghold.

Biden’s claims for the presidency rest heavily on foreign policy expertise gained in eight years as vice president and 34 years on the Senate Foreign Relations Committee. And, unusually for a Democratic candidate this cycle, he chose to speak about China.

“China is going to eat our lunch? Come on, man,” he orated. “They can’t even figure out how to deal with the fact that they have this great division between the China Sea and the mountains in the . . . west. They can’t figure out how they’re going to deal with the corruption that exists within the system . . . They’re not bad folks, folks, but guess what. They’re not competition for us.”

“This will not age well,” tweeted Sen. Mitt Romney, who surely remembers how then-President Barack Obama ridiculed him in the final 2012 presidential debate for bringing back the foreign policy of the 1980s by characterizing Russia as our “number one geopolitical foe.”

It turns out Romney had a point then, and he has one now. Biden’s foreign-policy views seem stuck in the 1990s.

Those were optimistic times, with the Cold War won and no geopolitical foe in sight, with a surging US economy complete with budget surpluses. It was “the end of history,” in scholar Francis Fukuyama’s phrase, when it seemed that something like the American-style democracy, human rights and dynamic capitalism would sweep the globe.

Including China. The mechanism to make it so was to bring China into the world trade system, a proposal supported by the Clinton administration, George W. Bush and most congressional Republicans. In 2000, permanent, normal trade relations with China passed the House 237-197 and the Senate 83-15. Opposition came largely from labor Democrats and members like Reps. Chris Smith, Frank Wolf and Nancy Pelosi concerned about China’s human rights abuses.

The widespread assumptions were that the international trade framework would lead China to respect international norms, and encourage the Chinese people to demand — and the Chinese government to advance — democracy and human rights. Increased trade, it was hoped, would produce economic growth here, as opening trade with Japan and Mexico had seemingly done.

These assumptions weren’t crazy or irrational. Unfortunately, they turned out to be wrong. The respected bipartisan experts of 20 years ago turned out to be wrong. Armchair critics like Donald Trump, then dismissed as cranks, turned out to be right.

China has consistently cheated on trade rules and intellectual property rights. And while increased trade with China has contributed to American economic growth, it has also cost far more American jobs than respected experts predicted.

Chinese imports as a percentage of US economic output doubled within four years, Massachusetts Institute of Technology economist David Autor reported in 2016. “We would conservatively estimate that more than a million manufacturing jobs in the US were directly eliminated between 2000 and 2007 as a result of China’s accelerating trade penetration in the United States,” in markets ranging from clothing to jewelry, toys to furniture, he wrote.

Hopes for democratization and human rights have also been dashed. China has become ever bolder in its suppression of human rights and any demand for anything like free elections. Chinese President Xi Jinping has even discarded the term limits imposed on his predecessors.

With economic growth slowing down, China’s leaders are evidently relying on expansionist nationalism to rally popular support. They have built and fortified islands in the South China Sea to claim sovereignty over its sea lanes and have expanded their capacity to nullify US weapons systems.

As former Trump Pentagon aide Elbridge Colby writes in Foreign Policy, “If the United States delays implementing a new approach, it risks losing a war to China or Russia — or backing down in a crisis because it fears it would.”

The hopes for a cooperative and peaceful China have unfortunately been dashed. But for Joe Biden, it’s evidently still the 1990s. Is this the best the Democrats can do?