Sen. Bernie Sanders hit back Monday after news broke that the centrist group Third Way is focus-testing attacks on Medicare for All to see what will stick, using a firm with close ties to former Vice President Joe Biden's 2020 Democratic presidential campaign.

"It is unfortunate but not surprising that Vice President Biden's polling firm is helping distort what Medicare for All is about," Sanders said in a statement. "My Medicare for All legislation eliminates all premiums, copayments, deductibles and out of pocket expenses that crush millions of Americans, which not only saves people money, it will allow all Americans to go to any doctor or hospital they want with no one expending more than $200 a year for prescription drugs."

Bloomberg reporter Sahil Kapur broke the news earlier in the day.

Scoop: A firm linked to Joe Biden tested messages to undercut support for Medicare for All among Democrats. Here’s what it found to be effective, and ineffective, at persuading 2020 primary voters.https://t.co/i0GIBnzL5O — Sahil Kapur (@sahilkapur) September 23, 2019

According to Kapur:

The survey, commissioned by the centrist Democratic think tank Third Way, found that primary voters start off favoring the government-run healthcare system by a margin of 79 percent to 21 percent, but can be persuaded to oppose it. The study showed that Democrats are most swayed by the arguments that the program would impose a heavy cost on taxpayers and threaten Medicare for senior citizens.

The poll was conducted by Lisa Grove of Anzalone Liszt Grove Research. Her partner, John Anzalone, is the chief pollster and an adviser to Biden, who opposes Medicare for All and wants to make government-run insurance optional.

Though Biden did not commission the poll, he and his team appeared on message Monday. In Iowa, Biden accused rival Sen. Elizabeth Warren (D-Mass.), who says she backs a Medicare for All system, of wanting to raise Americans' taxes.

Biden communications director Kate Bedingfield echoed that point during an appearance on MSNBC Monday. Bedingfield said that the Medicare for All bill presented by Sanders would make the cost of healthcare too high by raising taxes.

When reporter Katy Tur pushed back on that claim, pointing out that overall healthcare costs could be reduced by a Medicare for All system, Bedingfield pivoted and said that the real issue with the plan was that the runway to the system would take too long.

"I think the runway to get to Medicare for All is not the fastest way to get relief to those who need it now," said Bedingfield. "I think that building on the success of Obamacare is."

Sanders, in his statement, rejected that argument.

"Let me be clear: under my proposal no one earning less than $29,000 will pay any new taxes," Sanders said. "And for everybody else, except the very wealthy, what they will be paying in taxes will be far less than what they currently pay for premiums, copays, deductibles, prescription drugs and other healthcare expenses."

"Financially, Medicare for All will be a great deal for the American people," added Sanders.

News of the poll angered Demand Progress campaign director Robert Cruickshank.

"Health insurance is a protection racket," Cruickshank tweeted. "How awful do you have to be to take their side and undercut healthcare as a human right?"

In a tweet, Warren Gunnels, senior advisor to the Sanders campaign, called the tactics "disgusting" and laid out the ways Medicare for All would be an improvement over the current for-profit system.

Disgusting. A polling firm linked to Biden is working overtime to mislead Americans about #MedicareForAll by echoing bogus GOP talking points. Fact: #MedicareForAll improves benefits for seniors by covering: dental

vision

hearing

home care https://t.co/R04jmE25bo — Warren Gunnels (@GunnelsWarren) September 23, 2019

Third Way executive vice president for policy Jim Kessler told Bloomberg that the poll indicates the healthcare issue could be a winner for President Donald Trump.

"Trump is deeply underwater on healthcare and the only lifeline that could pull him to shore is Medicare for All," said Kessler.

However, the poll—which, again, Kessler's group commissioned—shows 53 percent of voters, a majority, are in favor of Medicare for All.