(CNN) While "Medicare for all" quickly became one of the top policy issues of the 2020 race for the Democratic presidential nomination, polling doesn't show a clear preference for a government-run health care program over the current system.

Many Americans don't really understand Medicare for all, and when they do, they're on the fence about some key issues. But, that confusion is particularly significant when it comes to the 2020 primary as Democrats are torn about what their party's nominee should focus on, with some big ideological divisions throughout the party, that could be cause for in-party fighting.

"I think it will be a divisive issue in the primary," said Mollyann Brodie, senior vice president at the Kaiser Family Foundation. "Especially if people start hearing about and learning about what it might mean, there's an issue of disruption. [P]eople get really anxious when you start talking about changing their current health arrangements. ... All of a sudden you see this tendency for reversion to the status quo. So, I think that that is a challenge that many of the Democratic candidates are going to have to nuance and pay attention to in the primary."

Medicare for all was the among the first big issues that candidates worked to address in 2020, having already been a main topic of conversation for Sen. Bernie Sanders from 2016. Sen. Kamala Harris made waves at her CNN Town Hall in April when she said she supported the proposal, something that would entail the public getting rid of their private insurance (since then, her campaign advisers have said she would be open to letting private insurance stick around).

Other candidates have promised they wouldn't get rid of private health insurance, while some are going full speed ahead on Medicare for all.

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