Source: POLITICO'S MORNING AGRICULTURE, 7/26/18

Farm groups have a multimillion-dollar message for Trump: His trade policies are hurting American farmers and manufacturers. Farmers for Free Trade, a nonprofit backed by the American Farm Bureau Federation and National Pork Producers Council, is investing $2.5 million in a four-month campaign aimed at showcasing how farmers are being harmed by the Trump administration's mounting trade war.

"Agriculture is a giant and it takes a while to wake it up, but when it wakes up you better watch out," said Brian Kuehl, executive director of Farmers for Free Trade, which is organizing the campaign.

All in the timing: The launch of the campaign comes as Trump is due to be in Iowa today, where he will likely reassure farmers growing increasingly nervous over retaliatory tariffs targeting soybeans, pork and other major farm commodities.

The centerpiece of the campaign is an advertisement set to run on Fox News, CNBC and CNN and in local television and radio markets in Iowa, Pennsylvania and Michigan. The ad calls out White House trade adviser Peter Navarro's July 19 remarks where he called the impact of tariffs a "rounding error."

"America's farmers and factory workers are not a rounding error," the ad says.