But they have not come close to the sort of public campaign that would put intense pressure on senators. History shows what such a campaign would look like:

In the 1940s, the American Medical Association (which represents doctors) conducted what was then “the most expensive lobbying effort in American history,” according to Paul Starr, author of a Pulitzer-winning history of health care. The campaign changed public opinion about Harry Truman’s plan for national insurance, helping doom it.

In the 1960s, the same association hired a movie star by the name of Ronald Reagan to barnstorm the country denouncing the proposal for Medicare. It would be the start of socialism, Reagan warned, and “invade every area of freedom as we have known it.” He lost that battle, but it set in motion his political career and modern conservatism.

In the 1990s, the lobbying group for insurance companies ran an ad campaign featuring a fictional couple named Harry and Louise. Sitting at their kitchen table “sometime in the future,” they lamented how much worse their coverage had become. The ads helped defeat Bill Clinton’s plan.

Today, however, “there isn’t much of a campaign,” as Starr told me. “And it contrasts very dramatically with some of the earlier conflicts.”

If anything, the case for an aggressive campaign is stronger now. Virtually every big health care group views the Republican plan as a disaster, one that would harm many Americans largely in the service of cutting taxes for the wealthy.