It’s easy to find mainstream people who hate the latest Republican effort to kill the Affordable Care Act. Because that’s almost everybody.

Doctors, represented by the American Medical Association, are against the Cassidy-Graham bill, which is the third and probably final effort to kill Obamacare this year. The American Cancer Society and just about all other patient advocacy groups are against it. So are insurers, drugmakers and hospitals. The AARP, the influential lobbying group for seniors, strongly opposes it. So do all Democrats everywhere, at least four Republican governors and some other conservatives.

Public approval of the Republican effort to kill Obamacare rests well below 20%, while approval of Obamacare itself has crested 50%. By some measures, the law Republicans want to kill is three times as popular as the law they want to replace it with. Public approval could go even lower as talk-show host Jimmy Kimmel continues his crusade against the Cassidy-Graham approach and other entertainers pile on.

Yet Majority Leader Mitch McConnell and his lieutenants are determined to try for a third time to kill Obamacare — and they might succeed. There will be just one public hearing on Cassidy-Graham before the Senate votes, and the Congressional Budget Office won’t even have time to analyze the bill’s likely effect on the federal budget and the number of Americans with insurance by then. If there were ever a ramrod piece of legislation that you’d think wouldn’t have a prayer, this is it.

Yet, there is a realistic chance the Senate will pass Cassidy-Graham in the coming days. If it does, the House will probably pass it as well, and President Donald Trump has said he’ll sign it. So how have we come to a point where Washington might enact legislation the majority of voters say they don’t want?

How could such hated legislation pass

Part of the answer may involve campaign money. The conservative Koch Brothers network has promised to donate up to $400 million to favored candidates in 2018, and two of their top agenda items are repealing Obamacare and cutting taxes. Koch-backed groups such as Americans for Prosperity, a super PAC, aren’t thrilled with the Cassidy-Graham bill, because they feel it doesn’t go far enough. The bill would end most of the ACA’s major provisions, and spend billions less on health care overall, probably leading to a big drop in the number of people covered by Medicaid. Many conservatives applaud cutbacks in this sprawling program that mostly benefits the poor.

Charles Koch (L) and David Koch are pictured in this combination photo. REUTERS/Freedom Partners Chamber of Commerce/Handout/Carlo Allegri More

Some conservatives feel the Cassidy-Graham bill still includes too much taxpayer funding for health care, which is why they’re lukewarm on the bill. But it’s probably the last chance to repeal Obamacare for the foreseeable future, because Senate rules change after Sept. 30, requiring 60 votes rather than 51 to pass most legislation. Killing Obamacare has a link to tax cuts, because it would free up some government revenue that could be used to lower tax rates. So for any Republican legislator hoping to fulfill the Koch agenda — and claim a share of the network’s campaign money — it all begins with killing Obamacare, no matter what the public thinks.

Republicans are also stuck with a foolish promise they made over and over for the past seven years — to repeal and replace Obamacare, even though there was no plan to replace it with. “They’re prisoners of their own promise,” says Jim Kessler, senior vice president at the centrist think tank Third Way. “If you’re a Republican, it’s better to keep the bad promise you made than reject what everyone knows is wrong.” Kessler, like others, says Republican legislators privately complain about being stuck in such an unpopular position. But the expedient thing to do is fulfill the promise first, then worry about the ramifications later.