Who would support single payer universal health care or Medicare for all?

[Uncle Joe]

25. Medicare for all would be building on what we have and Medicare is far more popular than the ACA

And more than two-thirds of respondents said Medicare needs to undergo at least some changes, however slight, to keep it financially stable in the future. A whopping 87 percent of respondents favored giving the federal government power to negotiate prescription drug prices with pharmaceutical companies, which President Barack Obama has proposed in his most recent budget plan.

Medicare and Medicaid, which in 2015 will cost more than $1 trillion in government spending, "are important programs to people," that "are really woven into the fabric of American lives," said Mollyann Brodie, a senior vice president of the Kaiser Family Foundation, and head of that group's survey team.

(snip)

However, Brodie noted that with regard to Medicare—the second most-popular government program after Social Security—"There is worry among younger Americans about whether it's going to be there for them" when they get old.

She also said that unlike the Affordable Care Act, which remains unpopular among Republicans, "We see much more across-the-board bipartisan support and agreement about these programs."

"Many more Americans feel that these programs are personally impacting their lives than are saying the same about Obamacare," Brodie said.

http://www.cnbc.com/2015/07/16/medicare-medicaid-popularity-high-ahead-of-birthday.html

Obamacare is not "extremely popular"

https://newrepublic.com/article/121614/obamacare-popular-kaiser-poll

Public opinion
Public opinion polls indicate that the United States public generally supports healthcare reform, but the public's views became increasingly negative in reaction to specific plans discussed during the legislative debate over 2009 and 2010. Polling statistics for the general population show a general negative opinion of the law in the first years; with those in favor at approximately 40% and those against at 51%, as of October 2013.[351][352] About 29% of whites approve of the law, compared with 61% of Hispanics and 91% of African Americans, according a Pew Research Center and USA Today survey conducted on 4–8 September 2013.[353] USA Today found opinions were strongly divided by age of the person at the law's inception, with a solid majority of seniors opposing the bill and a solid majority of those younger than forty years old in favor.[354]

Specific elements are very popular across the political spectrum, with the notable exception of the mandate to purchase insurance. FiveThirtyEight, describing public opinion of the law, said, "while surveys have consistently found that a plurality of Americans have an overall negative view of the Affordable Care Act, they have just as consistently shown that large majorities of Americans favor individual elements of the law."[355][356] For example, a Reuters-Ipsos poll during June 2012 indicated that 44% of Americans supported the law, with 56% against. By party affiliation, 75% of Democrats, 27% of Independents, and 14% of Republicans favored the law overall. Individual provisions of the law received varying levels of support: 82% favored banning insurance companies from denying coverage to people with pre-existing conditions, 61% favored allowing children to stay on their parents' insurance until age 26, 72% supported requiring companies with more than 50 employees to provide insurance for their employees, and 39% supported the individual mandate to own insurance or pay a penalty. By party affiliation, 19% of Republicans, 27% of Independents, and 59% of Democrats favored the mandate.[357] Other polls showed additional provisions receiving majority support include the creation of insurance exchanges, pooling small businesses and the uninsured with other consumers so that more people can take advantage of large group pricing benefits, and providing subsidies to individuals and families to make health insurance more affordable.[358][359] Other specific ideas that were not enacted but which showed majority support included importing prescription drugs from Canada (with its lower, government-controlled prices),[360] limiting malpractice awards, reducing the age to qualify for Medicare, and the Public health insurance option.[361]

Pollsters probed the reasons for opposition.[362] In a CNN poll, 62% of respondents said they thought the ACA would "increase the amount of money they personally spend on health care", 56% said the bill "gives the government too much involvement in health care", and 19% said they thought they and their families would be better off with the legislation.[363] Other polls found that people were concerned that the law would cost more than projected, and would not do enough to control the cost of health care affecting their families.[364]

However, part of the opposition to the law is because some Americans believe the reform did not go far enough: A Reuters-Ipsos poll indicated that, for those opposed to the bill, 71% of Republican opponents reject it overall while 29% believed it did not go far enough; independent opponents were divided 67% to 33%; and among the relatively much smaller group of Democratic opponents, 49% reject it overall, and 51% wanted the measure to go further.[357]

As of 2011 many Democrats believed that the ACA would grow more popular over time, like Medicare did after its implementation,[365] as the benefits of the law take effect and close the information gap about the contents of the bill.[355][356][366]

In June 2013, a majority of the public (52–34%) indicated a desire for "Congress to implement or tinker with the law rather than repeal it".[367] Following the Supreme Court upholding the constitutionality of the individual mandate in National Federation of Independent Business v. Sebelius, a poll released in July 2012 showed that "most Americans (56%) want to see critics of President Obama's health care law drop efforts to block it and move on to other national issues."[368] The RAND Health Reform Opinion Study for May 1, 2014, showed that 48.9% of respondents had an unfavorable view of the ACA vs. 38.3% who had a favorable view (of more than 5,500 individuals).[369]

Polling averages from RealClearPolitics showed public approval of the ACA as 52.1% against and 38.6% for (poll averages from February 27 to March 25, 2014).[351]

An Associated Press-GfK poll released March 28, 2014 showed that 26% of Americans support the ACA.[370]

A Wall Street Journal/NBC poll released April 30, 2014, indicated that 8% of respondents say that the Affordable Care Act "is working well the way it is."[371]

By the end of 2014, a Rasmussen 3-option poll showed Repeal: 30%, Leave as is: 13%, Improve: 52%, i.e., 65% wanted to leave the ACA alone or improve upon it.[372]

In June 2015, a CBS News/New York Times poll showed that 47% of Americans approved the health care law. This was the first time that a major poll indicated that the number of Americans who approved the ACA is bigger than the ones who disapprove it, though by a small margin.[373]

https://en.wikipedia.org/wiki/Patient_Protection_and_Affordable_Care_Act

While I do believe Obamacare has some great features about it, the policy also some major shortcomings, institutionalizing the for profit health insurance industry being just one. Their profits having nothing to do with actual health care, that system is dysfunctional.

Not being able to negotiate lower drug prices being another.