Rachel Lockwood was on a mission when she drove more than 150 miles from Greenville to Detroit Sunday morning with three of her eight kids.

She hopped on a bus to Windsor with U.S. Sen. Bernie Sanders, a Democratic candidate for president, with the goal of finding insulin in Canada at a fraction of the cost for what she pays for the drug in the United States.

Three of her kids, Jocelyn, 16, Brady, 12, and Cyrus, 7, all have insulin-dependent Type 1 diabetes. The American version of insulin is $620 per box, which lasts about six weeks. The same thing in Canada costs $100 per box.

"Because our youngest was just diagnosed five months ago, we had been sharing the insulin between the two children, but when we had a third diagnosed with type 1, we couldn't stretch it anymore," Lockwood said. "They all have Medicaid and up until about eight and a half years ago, they were covered. But then, all of a sudden, we got notice that what they had been using was no longer going to be covered."

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It was Lockwood's story, along with a dozen other people with diabetes, that prompted Sanders, as part of his presidential campaign trip to Detroit for Tuesday's debate in Detroit, to charter a bus in Detroit and head to the Olde Walkerville Pharmacy in Canada.

The families' stories provided a focal point to Sanders' argument that corporate greed, fueled by political contributions to campaigns, could only be stopped by progressive policies.

"As Americans, what we have to ask ourselves is how come the same exact medicine, in this case insulin, is sold here in Canada for one-tenth of the price that was sold in the United States," Sanders said. "And it has everything to do with the incredible greed of the pharmaceutical industry."

Sanders is one of 20 Democratic candidates for president who are headed to Detroit for two nights of debates on Tuesday and Wednesday at the Fox Theater, hosted by CNN.

As a result, candidates are capitalizing on the debate to set up other events to meet with Michigan voters, a key battleground state in the 2020 election cycle. After Michiganders gave Democratic presidential candidates victories in every election dating back to 1992, Republican Donald Trump beat Democrat Hillary Clinton in the state in 2016 by a mere 10,704 votes out of nearly 4.8 million votes cast.

South Bend Mayor Pete Buttigieg, was set to appear at a fundraiser at the Filmore Theater in Detroit Sunday evening, while former U.S.Housing and Urban Development Department director Julian Castro was scheduled to attend an event in Eastern Market Monday evening and U.S. Sen. Cory Booker will wait till the debates are over on Thursday night to attend a campaign event at St. Andrew's Hall in Detroit.

On Sunday afternoon, however, the campaign trail was focused on diabetes patients who said they often have to choose between rationing medicine and paying their electric bills.

Quinn Nystrom, of Baxter, Minnesota, said that often, only the wealthy can take time off work and afford the expense of traveling to Canada for medication.

What (the phramaceutical companies) are doing to Americans is price gouging us and they're holding us hostage and people are dying," she said.

Stephanie Odette, 30, of Berkley, said she and her husband would like to start trying to have a family, but they're nervous about passing diabetes along to a baby and are often hit with big medical bills, especially since she's been admitted to the hospital intensive care units 74 times in the last 10 years.

Her husband's insurance is good, but doesn't cover the specific brand of insulin that she requires.

"I'm genetically predisposed to pass it on to my child. So you already feel like a monster. So it's been a really difficult thing for our marriage. It's been a difficult thing for my family. My mom thinks it's going to be like Steel Magnolias, and I'm going to get pregnant and die," she said referring to the 1989 movie starring Sally Field, Julia Roberts and Shirley MacLaine. "And you just want to have a normal life."

Contact Kathleen Gray: 313-223-4430, kgray99@freepress.com or on Twitter @michpoligal.