With the Michigan Democratic primary contest coming up on March 8, presidential hopefuls Bernie Sanders and Hillary Clinton are taking vigorous jabs at each other’s positions on trade amid concerns about the future of the state that once was a booming manufacturing hub.

Sanders, for the most part, has been making sharp contrasts with the former secretary of state’s judgment on trade. At campaign stops in Detroit this week, the Vermont senator called Clinton a “outsourcer in chief.” He told supporters that Clinton supported controversial trade deals such as the North American Free Trade Agreement under her husband’s administration. Close video Clinton Lays Out Jobs Plan In Detroit CNBC’s John Harwood discusses his interview with Hillary Clinton on her economic plan. Then, MTP Daily gets reaction from Brian Fallon of the Clinton campaign and Tad Devine of the Bernie Sanders campaign. CNBC’s John Harwood discusses his interview with Hillary Clinton on her economic plan. Then, MTP Daily gets reaction from Brian Fallon of the Clinton campaign and Tad Devine of the Bernie Sanders campaign. share tweet email Embed

“All of these trade agreements together have cost us millions of decent-paying jobs, led to the de-industrialization of America and the decline of the American middle class,” said Sanders on Friday, who noted that he had fought against virtually all trade deals since he was a junior congressman.

On the campaign trail, Sanders often uses Clinton’s reversed position on the Trans-Pacific Partnership (TPP) to portray her as a flip-flopper. The former first lady announced her opposition to the TPP last October, six months into her presidential campaign, in an interview with PBS NewsHour’s Judy Woodruff. “I don’t believe it’s going to meet the high bar I have set,” Clinton said. She helped in early negotiations of the deal while serving as President Obama’s secretary of state, at one point calling it the “gold standard.”

Clinton fended off Sanders’ attacks on Friday in Detroit, saying, ”Anyone running for president owes it to you to come up with real ideas, not an ideology, not an old set of talking points but a credible strategy designed for the world we live in now.”

She added that, on trade, the next president would need “judgment and experience.” Clinton also criticized Sanders for his lack of a detailed manufacturing plan and opposition to the Federal Export-Import Bank, which helps foreign consumers purchase American goods.

Clinton also released an ad in Michigan targeting companies that are moving their operations overseas to avoid paying American taxes and reduce labor costs. The ad points to Clinton’s proposal of an “exit tax” for such companies.

Sanders also debuted a television ad this week, asserting his consistent position on issues relating to trade and manufacturing. “While others waffle, Bernie is fighting hundreds of thousands in new job losses,” the ad says.

The candidates meet in Flint, Michigan, on Sunday night for a Democratic presidential debate hosted by CNN.