"That means that the debate over Medicare-for-all changes, and I think that is what is happening now."
Indeed, Sanders' Medicare-for-all bill, which would create a new government plan like Medicare for everyone, has drawn support from nearly every major Democrat in the Senate who is expected to seek the 2020 presidential nomination.
But many Democrats who aspire to something like Sanders' proposal still worry about the cost and disruptions that would likely be necessary to create a large new government plan for everyone.
"I share the desire for universal coverage," said Bennet. "The question is what approach is more practical to achieving that objective."
Nearly a decade ago, Democratic leaders, concerned about the politics of expanding government health plans too aggressively, created the Obamacare insurance marketplaces, which rely on private insurers to provide coverage for Americans who don't get health benefits through an employer or through a government program.
Democrats even rejected a proposal for a limited government plan to be sold on the marketplaces as a "public option."
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But the ceaseless GOP attacks on the marketplaces, which had been a conservative idea, and the failure of private health insurers to make more affordable plans available -- even before Trump took office -- has caused more Democrats to back a bigger role for government.
"That is a huge shift," said Jacob Hacker, a Yale political scientist who helped develop the public option proposal.
Further emboldening Democrats is growing evidence that the public overwhelmingly supports existing government health plans, especially in the face of GOP threats to scale them back.
And majorities of both parties favor allowing more people to buy into the program, the survey found.