A quick history of single payer:
In 1932 half the country was out of work and people were still getting sick and dying. America turned into one giant blockade by 1934. To stop this blockade, Congress (led by a reluctant traitor to his filthy rich class, Franklin Roosevelt, who at least was a sharp politician) passed much of the New Deal, which barely worked.
Meanwhile, Germany, Italy and Japan had economic revolts which only put worse crooks in power, and the crooks declared war on every other country and 90% of their soldiers were killed. To prevent this from happening twice and to build up foes against the expanding Soviet Union, Roosevelt and Truman did the right thing. Germans and Japanese got real healthcare for all. Back home, the owners of America wouldn't let us get it.
Single payer was wildly popular the world over, especially the plans that let chiropractors and naturopaths in too. Decades ago, every other wealthy country on earth swung over to single payer with outcomes-based medicine.
President Obama and the Dems thought, can we harness this wildly popular system to a process of huge wealth extraction for our friends? They forced it through. Yep, it was at least 10% more popular than killing grandma, the Republican plan.
The Republicans violently fought back, insisting that killing grandma was patriotic, moral and Christian. The meme didn't sell!! So now the Republicans are looking for a new and improved meme that will sell better. The Dems, for their part, are still desperately trying to save as much superfluous wealth extraction as humanly possible. On the side, the MD community fights the chiropractors tooth and nail to keep them out of the gravy train.
Then there's the voters. Who are they?