President Donald Trump speaks with reporters as he departs the White House, in Washington, DC, on May 30, 2019. Jim Watson | AFP | Getty Images

President Donald Trump heads to Iowa on Tuesday as he tries to limit the political damage from tariff crossfire that has scarred the U.S. heartland. The Hawkeye State has — at least briefly — exhaled after the White House decided not to ramp up its trade conflict with Mexico, Iowa's second-largest export market. But ongoing damage in Iowa from the president's economic war with China has left Trump taking steps to shore up support in the state ahead of his 2020 reelection bid. Trump will tour a renewable energy facility in Iowa on Tuesday afternoon before heading to a state GOP fundraiser. The events follow his administration's decision late last month to allow year-round sales of E15 fuel, a blend with a higher concentration of ethanol. Higher E15 sales will not only help ethanol producers but also boost demand for Iowa's corn. Trump will have more he wants to promote in Iowa, a swing state that President Barack Obama won twice before Trump carried it in 2016. On Thursday, he signed a disaster relief bill that will give aid to areas of the state ravaged by flooding. (Trump's opposition to sending more relief money to Puerto Rico contributed to months of delays for the legislation.) In late May, the Trump administration also announced a plan to distribute $16 billion in aid to farmers damaged by tariffs. "Is the administration concerned about Iowa? I hope they are," said David Oman, a consultant who was chief of staff to two Republican governors of Iowa and co-chair of the state GOP.

Farmers are patient ... for now

Iowa is particularly vulnerable to shots in Trump's trade war. It not only ranks among the top U.S. producers of soybeans and pork — items hit by China's retaliatory tariffs — but also relies on free trade with Mexico and Canada. Damage to the state's farmers can ripple to manufacturers and consumer spending. Trump's trip to Iowa on Tuesday shows an effort to contain the damage from his trade policy — especially as Democratic presidential candidates swarm the state ahead of its first-in-the-nation caucuses in February. Trump won the state and its six electoral votes by about 9 percentage points in 2016. But his popularity in the state has fallen from its pre-inauguration highs. In May, 42% of registered voters in Iowa approved of the job Trump is doing, versus 54% who disapproved, according to a Morning Consult poll. But there's little to suggest the president's core supporters abandoned him as the trade war widened. In March, a Des Moines Register poll found 81% of registered Iowa Republicans approve of the job Trump is doing — unchanged from a December 2018 survey. Oman said Iowa farmers have been "surprisingly patient" as Trump tries to strike a trade deal with China. While he noted that Iowa has cheered the ethanol rules change, he called the aid package a "short-term fix at best" for farmers damaged by the tariffs. "How much longer they will remain patient is hard to understand, hard to know," he said.

Democrats mostly avoid trade talk

Only a few Democratic presidential candidates have tried to capitalize on Trump's trade policy. Most have not directly addressed tariffs in the state. They have instead focused on issues such as health care, infrastructure, the consolidation of big agriculture companies and addressing climate change to curb flooding in Iowa. Former Rep. Beto O'Rourke — who represented a border area of Texas reliant on trade with Mexico — has criticized Trump's tariffs more often than most of his competitors. In a CNN column last month highlighting his talks with Iowa farmers, O'Rourke wrote that "China isn't paying the price for this reckless trade war. We are."

Former Vice President Joe Biden will also take shots at the president's tariff policy when he heads to Davenport, Iowa, on Tuesday. "America's farmers have been crushed by [Trump's] tariff war with China. No one knows that better than Iowa," Biden will say, according to remarks prepared for delivery shared by his campaign. Also during the speech, he planned to call Trump an "existential threat" to the U.S. As he prepared to leave for Iowa on Tuesday, Trump listed the reasons he would want to face Biden in 2020 — calling the former vice president a "loser" and mentally "weak." He also argued "the best thing that ever happened to the farmers is me," citing in part the aid package for farmers. "We gave them ethanol at 15 which nobody was ever going to do, which Biden didn't do in eight years as vice president," he told reporters. "The farmers are my best friend. Nobody has treated the farmers better than Donald Trump." Trump still could end the trade pain in the Midwest well before the November 2020 election. His administration hopes to strike a trade deal with China in the coming months. A deal could include increased agricultural purchases by Beijing.

Hopes for a deal, fears for the future