For decades before Obama burst onto the political scene, liberals had been pushing for the federal government to establish some sort of national health care program.
But this effort always ran up against the same obstacle - an overwhelming majority of Americans were happy with their coverage and were leery of any changes.
So the health care status quo prevailed again and again, but most prominently when President Clinton's health care reform effort went down in flames in 1994.
Eventually, Democrats learned that whenever proposing changes to the health care system, they had to emphasize that the changes wouldn't affect those who already had coverage they liked.
In 2007, when Obama was still considered a long shot to win the Democratic presidential nomination, then-frontrunner Hillary Clinton was barnstorming early primary states telling audiences that under her universal coverage proposal, "If you have health insurance, and you like it, you keep it, no questions asked."
When Obama took office and made health care his top priority, he understood that one of his main tasks was to convince Americans that he had a plan that could improve the health care system for those who it wasn't currently working well for (such as those with pre-existing conditions) while leaving it untouched for those who were satisfied.
"I know that there are millions of Americans who are content with their health care coverage -- they like their plan and they value their relationship with their doctor," he told the American Medical Association in June 2009.
"And that means that no matter how we reform health care, we will keep this promise: If you like your doctor, you will be able to keep your doctor. Period. If you like your health care plan, you will be able to keep your health care plan. Period. No one will take it away. No matter what," Obama said.
In September 2009 -- the same month Obama made his health care pitch to a special joint session of Congress -- a Gallup survey found that 87 percent of Americans with private insurance were satisfied with their medical care.
Obama knew that a lot of people would lose their coverage. Even if there was nothing in the law that explicitly ordered Americans to get rid of their insurance, legislation that made such sweeping changes to the insurance market inevitably was going to create disruption.