Detroit (CNN) As the 2020 Democrats fan out across the country trying to convince voters they would be better shepherds of the US economy than President Donald Trump, some Democrats like former Michigan Gov. Jennifer Granholm are questioning whether they are connecting with the voters of the industrial Midwest who believe Trump is fighting for them.

During the "Citizen by CNN" event Sunday night in downtown Detroit — where CNN will host Democratic debates on Tuesday and Wednesday , Granholm, a CNN contributor, noted that Trump won states like Michigan, Wisconsin and Pennsylvania in part by vowing to undo unpopular trade deals and bring industry back to the US.

"People who are in blue collar jobs feel like at least he's trying something, right? That is the challenge for Democrats. Because what he's trying is actually not working," she said. "Those stories, they need to be brought out because what he's doing is ineffective and worse, it's hurting workers. But Democrats have got to be able to make that case."

CNN interviews with voters in swing states across the country suggest that some of the leading Democrats could face two central problems as they look ahead to the general election contest in 15 months: one, most American voters are far more moderate than the far-left activists the candidates are courting to win the primary, and two, many Americans feel positive about the economy.

It is the one bright spot in Trump's abysmal poll numbers, and clearly a factor that is bolstering his approval rating. An NBC News/Wall Street Journal poll from this month had Trump's approval rating among voters nationwide at 45% with a disapproval rating of 52%. In a CNN poll from June , 52% of voters approved of how Trump is handling the economy.

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