Leaders of some of America's largest labor unions are speaking out against centrist Democratic presidential candidates who, in an effort to undercut Medicare for All, are pitting unionized workers against millions of uninsured Americans.

Former Vice President Joe Biden, Rep. Tim Ryan (D-Ohio), and former Rep. John Delaney (D-Md.) have each argued in recent days that Medicare for All would undo the hard-won collective bargaining gains of unions by replacing employer-sponsored health insurance with a single-payer program.

"I really resent the 16 million workers who joined together and bargained for better health plans being pitted against millions of Americans struggling to get healthcare coverage."

—Mary Kay Henry, Service Employees International Union

As Common Dreams reported last month, the Biden campaign released an ad featuring a retired union worker named Marcy, who said she "earned" her private insurance and wants to keep it.

Ryan and Delaney echoed the message of Biden's ad during the Democratic presidential debate in Detroit on Wednesday, accusing Sens. Elizabeth Warren (D-Mass.) and Bernie Sanders (I-Vt.) of throwing union workers under the bus by backing Medicare for All.

"We have all our union friends here tonight," said Ryan. "This plan that's being offered by Senator Warren and Senator Sanders will tell those union members who gave away wages in order to get good healthcare that they're going to lose their healthcare because Washington's going to come in and tell them they got a better plan."

HuffPost labor reporter Dave Jamieson said Service Employees International Union (SEIU) president Mary Kay Henry seemed "genuinely angered" when asked about the argument that Medicare for All would hurt union workers.

"I think it's a false choice," said Henry, "and I really resent the 16 million workers who joined together and bargained for better health plans being pitted against millions of Americans struggling to get healthcare coverage."

I asked @SEIU president @MaryKayHenry what she thought of this argument (floated by Biden and others) that Medicare for All would hurt union workers who have good health plans. She seemed genuinely angered by it: pic.twitter.com/Y4flTEpRsQ — Dave Jamieson (@jamieson) August 1, 2019

Henry was not alone.

Sara Nelson, president of the Association of Flight Attendants, told Vox that she found Ryan's argument "offensive."

"It is real that there is work to do with unions," Nelson said. "People do love their contractural plans. But not every union contract today has exemplary healthcare."

This is how most Americans experience our for-profit healthcare system. That means those of us with better plans are screwed because we can’t hold off where this is going — it is unsustainable. And, people are dying because of it. Enough! - Your friendly union president https://t.co/SeEKfmK8LI — Sara Nelson (@FlyingWithSara) August 1, 2019

Democratic opponents of Medicare for All neglected to mention the fact that National Nurses United (NNU), America's largest nurses union, is leading the grassroots organizing for single-payer across the country.

NNU tweeted during the Democratic presidential debate Tuesday night that "Medicare for All would put money back into union members' pockets in the form of wages and other benefits."

"That's why major unions representing millions of workers in the U.S. are in this fight," said NNU.

Rep. Pramila Jayapal (D-Wash.), who herself has voiced frustration with fellow Democrats' misleading attacks on Medicare for All, thanked union leaders for "pushing back on these falsehoods" in a tweet on Thursday.

While some prominent unions—most recently the International Association of Fire Fighters, which endorsed Biden for president—have expressed opposition to Medicare for All, more than 20 unions representing over 10 million workers have endorsed Jayapal's Medicare for All legislation, including the American Federation of Teachers, the United Automobile Workers, and the United Mine Workers of America.

"We have an unprecedented labor coalition supporting [Medicare for All]," Jayapal said, "because soaring healthcare costs are directly tied to stagnating wages and hurt workers at the bargaining table."