Perhaps the health care industry has lost its lobbying mojo.

Despite a mystique that K Street controls the unseen levers of power in Washington, a contingent of well-known and flush-with-cash groups representing doctors, hospitals, patients and seniors appears so far unable to kill — or significantly alter — a bill its members despise.

The opposition of the American Medical Association, American Hospital Association, AARP and other prominent groups did not stop the House from passing its version of a replacement for the 2010 health care law. Now, those lobbies are searching for the precious few pressure points to help derail the Senate bill.

It’s already clear that the political forces driving the bill, or the ones that might ultimately take it down, are bigger than they are.

After all, this is about a promise Republicans repeated for four elections: to undo Obamacare.

“And that’s been powerful,” says Dean Rosen, a partner at Mehlman Castagnetti Rosen & Thomas, who served as chief health care adviser to then-Senate Majority Leader Bill Frist, the Tennessee Republican.

During negotiations over President Barack Obama’s law, Democrats brought nearly all health care industries into the fold, often by using threats of deeper cuts or bigger problems if they didn’t join the talks. Democrats didn’t want a repeat of the 1990s health policy battle when the insurance industry’s famous Harry and Louise ads did in Hillarycare.

While they may have been strong-armed, many of these interest groups got on board so they could influence the details of what became law. That isn’t the case this time.

“I just don’t think the inside lobbying game is going to be as effective as it was in 2009,” says Richard Hall, a political scientist at the University of Michigan, who studies lobbying campaigns.

That’s because Republicans have sought limited feedback, while the closed, leadership-driven process for hatching the bill makes it all the harder to lobby. Only in recent weeks did the Senate version become public — displaying deep cuts to Medicaid and sparking a backlash.

“I don’t recall any piece of legislation that I’ve worked on before that’s been so secretive and devoid of input,” says David Certner, a veteran lobbyist with the seniors group AARP.

Stacey Rampy, a partner in the health care lobbying firm Rampy Northrup, says it’s a far different experience than lobbying Obamacare, which had 18 months of hearings. “There were multitudes of meetings not only with Congress but with the administration, so it’s a very different animal,” she says.

Congressional Republicans, keenly aware that many of the most prominent health lobbies are reticent to wholly upend the current law, view those groups with some skepticism.

“The Republicans knew that people who are invested in the entitlement, people who are invested in supporting very vocally the Affordable Care Act, were going to be at a minimum disappointed and likely opposed to changes that would include rolling back that entitlement,” Rosen says.

Such groups, though, have not abandoned the GOP.

The AMA and AHA each contributed about $2 million to candidates in the 2016 cycle, with slightly more to Republicans, according to the nonpartisan Center for Responsive Politics. They are in the top five of lobbying spenders over the past two decades.

Still, like all players, they’ve been adjusting to a new political reality this year with President Donald Trump, who has admitted he didn’t grasp the complexities of health policy minutiae.

“A lot of the early opposition to repeal and replace is pretty lukewarm. They weren’t coming out as strongly in opposition, weren’t running ads or putting on high pressure campaigns because they felt like they needed to figure out a new relationship with the Republican government,” Hall says.

Some groups, including AARP, ran ads during the July Fourth recess, working to mobilize voters against the plan in states such as Nevada, Ohio and West Virginia with GOP senators who have expressed opposition or concerns. Sen. Dean Heller of Nevada, the GOP’s most vulnerable senator, faces re-election in a state that Hillary Clinton won. He is focused on what his voters want.

That sort of constituent effort may pay off where traditional lobbying can’t.

“These are large-scale political dynamics that any single company or industry doesn’t get to shape,” says Lee Drutman, author of “The Business of America is Lobbying.”

But maybe the voters can — with a little nudging from K Street.