Democrats are pessimistic that Congress will enact new rules around the health insurance industry, even as they try to appear responsive to growing calls for reform following the killing of UnitedHealthcare CEO Brian Thompson.   Luigi Mangione faces murder charges for the killing of Thompson on December 4. His death unleashed a torrent of anger on social media against the U.S. health system, and insurance companies specifically.   It also opened an uncomfortable national discourse about whether the health executive deserves sympathy, given the profits his company made while denying a relatively high percentage of claims.  "We can't be indifferent in this moment when there's so much anger at the private insurance companies, where we're hearing story after story of people with cancer, with heart disease or diabetes or having their claims denied,” said Rep. Ro Khanna (D-Calif.).  While politicians have roundly comdemned the violence, the apparent assassination has exposed the deep cynicism with which much of the public, on the right and the left, sees the insurance industry.  Sen. Rafael Warnock (D-Ga.) said the incident was a "flash point," but he wasn't sure how much impact it would have in spurring any changes.  “I think if we're listening to the people in our states, we'll be focused on this,” Warnock said, but “I don’t know” if the incident will spark conversations on reform.  Criticism of the insurance industry stretches back to before the Affordable Care Act put major changes into place.  As a result of the 2010 law, young people can stay on their parents’ insurance up to the age of 26. Health insurers now need to cover a defined list of essential health benefits including hospitalizations, maternal and newborn care and prescription drugs. They also can’t charge people more or deny coverage if they have pre-existing conditions.  But while the law dramatically expanded health coverage, it wasn’t a remake of the entire health system. It didn’t entirely address the underlying reasons why care is so expensive, which include prescription drug prices and provider reimbursements, said Cynthia Cox, a vice president at health policy research nonprofit KFF.   Health spending has continued to rise, and individual consumers are often stuck with large out-of-pocket costs on top of what they may pay monthly for their insurance premiums.  “The entire U.S. health system is to blame, certainly not just insurance companies,” Cox said. “When you look at health spending it's because we spend so much more on inpatient and outpatient care, more so than drugs or overhead or insurance. “  Yet a consensus on what to do about it remains elusive in Congress.  “You can get bipartisan consensus if you're willing to do the work,” said Sen. Tim Kaine (D-Va.), pointing to efforts to reform the pharmacy benefit manager (PBM) industry. “We got a really nice bipartisan consensus in the HELP Committee on PBM reform ... and then nobody ever did the work to get them queued up on the floor.”  Progressives say the answer is single payer, effectively consolidating the insurance market in a government agency. Some centrists want more government regulation, while some on the right question whether health coverage is necessary at all.    “I'm open to seeing if there's a Republican who would support at least bipartisan legislation of not having your claims denied if a doctor prescribes something that Medicare would cover,” said Khanna, a progressive supporter of Medicare for All.  While insurance companies may only be one side of the cost equation, public resentment against them has never been higher. And people aren’t just mad about prices.   “We're in a moment where the discontent has really boiled over and is being laid bare for all to see,” said Sachin H. Jain, the CEO of SCAN Group, a nonprofit Medicare Advantage insurer. “I think that there's a degree of heightened awareness of what many of us have kind of observed a long time about American health care, which is that we've normalized a lot of practices that are, frankly abnormal.”  Critics point to policies like prior authorization, where insurers require doctors and patients to get permission before undergoing a procedure, or step therapy, which requires patients to try a lower cost drug or treatment before “stepping up” to a more expensive one.  Health plans argue they are saving consumers money and cutting down on unnecessary procedures. But critics charge that insurance companies are just denying care to boost their own profits.  A Gallup poll released last week showed Americans’ positive view of the quality of health care in the U.S. “is now at its lowest point” since 2001.  Police are still piecing together a motive for Thompson’s alleged shooter, though a short, handwritten document found on Mangione at the time of his arrest made it clear that he was furious at the health care industry.   While lawmakers decried violence as a solution to any problem, they said the public anger and desire for change is understandable.  “I've long said violence, murder, are always unacceptable, always. But I think that there is a context, you know, here that is hugely important,” said Sen. Ron Wyden (D-Ore.), chairman of the Senate Finance Committee.   “People who have coverage, who have a good employer package feel like they're kind of one serious illness from being in very difficult kind of circumstances,” Wyden added.     Rep. Alexandria Ocasio-Cortez (D-N.Y.) told CBS News that Americans see a denied insurance claim as an “act of violence.”  “This is not to say that an act of violence is justified but I think for anyone who is confused or shocked or appalled, they need to understand that people interpret and feel and experience denied claims as an act of violence against them,” Ocasio-Cortez said.  However, Mangione did not have an insurance policy through UnitedHealthcare, the company said, and it’s not clear if he was ever denied an insurance claim.