WASHINGTON — Democratic presidential candidates clashed in a Tuesday night debate over how they would change course from President Trump’s protectionist trade agenda in fiery exchanges that underscored the depth of the rift within the party over economic policy.
The strength of the United States economy, which has enjoyed steady growth and historically low unemployment in recent years, represents Mr. Trump’s greatest asset going into his re-election campaign and a conundrum for Democrats. On Tuesday night, the candidates strained to paint what Mr. Trump touts as an economic miracle as a mirage, pointing to widening income inequality and trade policies that they argue have done American workers more harm than good.
For two and a half hours, moderate and progressive candidates grappled with whether pragmatism or idealism was the best formula for defeating Mr. Trump next year. It was the subject of trade, which has become the centerpiece of Mr. Trump’s agenda, that most animated the candidates. They argued over whether to revisit Obama-era multilateralism or double down on Mr. Trump’s brand of economic isolationism, which has upended how both Republicans and Democrats think about international commerce.
The most striking example of the fissures came during a heated exchange between Senator Elizabeth Warren, a progressive from Massachusetts, and John Delaney, a moderate former congressman from Maryland, during an argument over what should be done about Mr. Trump’s steel tariffs.
“I’m the only one running for president who actually supports the Trans-Pacific Partnership,” Mr. Delaney said, referring to the 12-nation trade pact that Mr. Trump abandoned upon taking office. “President Obama was right about that. We should be getting back in that.”
Deriding Ms. Warren as an isolationist on trade, he added: “We have to engage.”
[Here are six takeaways from Tuesday night’s debate.]
Ms. Warren unveiled a trade plan this week that included a raft of strict preconditions on human rights and environmental standards that would be required for kicking off any negotiations with other countries. On Tuesday night, she vowed to sideline big corporations and make sure that unions, small farmers and environmentalists took priority in future trade talks.
“For decades we have had a trade policy that has been written by giant multinational corporations to help giant multinational corporations,” Ms. Warren said. “They have no loyalty to America.”
Not to be outdone, Senator Bernie Sanders of Vermont said that he would stop giving military contracts to companies that did not employ American workers to manufacture their products.
“If anybody here thinks that corporate America gives one damn about the average American worker, you’re mistaken,” said Mr. Sanders, a self-described democratic socialist. “If they can save 5 cents to Mexico or China or Vietnam, that’s what they’ll do.”
Republican and Democratic positions on trade have gyrated in recent years as Mr. Trump has employed tariffs, with limited success, as a tool for rebalancing America’s trade relationships. It was less than four years ago that President Barack Obama concluded years of negotiations with Pacific Rim nations to join the Trans-Pacific Partnership, a trade pact widely seen as countering China’s rising economic dominance in the region. But the deal floundered in Congress and was shunned in 2016 by Mr. Sanders and Hillary Clinton, the leading Democratic candidates that year, as Mr. Trump began to outflank them on trade.
The more moderate Democrats were more cautious in their attacks on Mr. Trump’s stewardship of the economy, largely taking issue with sluggish income growth and what they called the unfairness of the tax code while criticizing his methods on trade.
For instance, when asked whether they would repeal Mr. Trump’s tariffs on steel imports, most of the 10 candidates hedged.
“He’s bungled the whole thing,” said Representative Tim Ryan of Ohio, explaining that he would “re-evaluate” the steel duties while acknowledging some alignment with Mr. Trump’s China policies.
“Look, I think President Trump was onto something when he talked about China,” Mr. Ryan said. “China has been abusing the economic system for a long time.”
When it comes to dealing with China, the candidates generally agreed with Mr. Trump on taking a tough approach. Much depends on who wins the nomination, and whether that Democrat goes on to win the White House. But the rhetoric suggests that the economic relations between China and the United States could continue to be strained no matter which party wins the presidency next year. Thorny issues will remain even if Mr. Trump strikes a trade deal with China before the election, as the United States pushes Beijing to loosen its grip on the world’s second-largest economy.
Still, they offered little detail about how they would achieve better results than Mr. Trump beyond diminishing the influence of corporate lobbyists and fostering greater cooperation with allies.
John Hickenlooper, the former governor of Colorado, outlined a give-peace-a-chance approach with China, arguing that “trade wars are for losers” and that the dispute with China cannot be won with tariffs, which he described as a tax on the middle class.
“There is a way of looking at trade that is therapeutic,” Mr. Hickenlooper said.
Despite the strength of the economy, some economists argue that it has thrived in spite of Mr. Trump’s agenda. The trade tensions caused by his tariffs are widely acknowledged to have been a drag on economic growth. The federal budget deficit has increased an average of 15 percent for each fiscal year he has been in office.
Moreover, Mr. Trump’s handling of trade negotiations has called into question his deal-making prowess. The overhaul of Nafta is languishing in Congress, where it must be ratified. A new trade war with Europe is brewing over digital taxes. Negotiations with China, which resumed this week in Shanghai, appear to be making little progress.
Mr. Trump blames Democrats for many of his trade challenges. Ahead of the debate on Tuesday, the president said countries like China were rooting for one of his would-be successors to replace him so they could get better trade deals with someone else in the White House.
“I think if China had their wish, they’d wait until after the election, they’ll pray that Trump loses, and then they’ll make a deal with a stiff,” Mr. Trump said.