At a town hall meeting in June, confronted by voters furious that he might vote to rewrite the Affordable Care Act, Sen. Bill Cassidy (R-La.) made this vow: "I will judge the final product as to how well it addresses the issue of preexisting conditions."

But his pledge and similar ones made all year by other leading Republicans have been belied by the text of a bill bearing Cassidy’s name, which would slash federal funding for Medicaid and private insurance coverage, and replace many ACA rules with block grants to states.

While a sentence in the 140-page bill says that states would have to explain to federal officials how they would “maintain access to adequate and affordable health insurance coverage for individuals with preexisting conditions,” another clause starting on the next page would undercut this core ACA safeguard by letting states allow insurers, once again, to charge higher prices to customers with a history of significant illness.

This part of the plan is weighing heavily on Maine Sen. Susan Collins (R), who helped defeat a GOP health-care plan in late July and remains a key lawmaker should Senate Majority Leader Mitch McConnell (R-Ky.) still try to bring the bill to a vote next week.

Speaking in Portland on Friday, Collins said she was “leaning against” the legislation, in part because it would undermine protections for people with preexisting conditions. While they would have to be offered coverage, “their premium could be so high that it would not be affordable,” she said.

Late-night TV host Jimmy Kimmel has repeatedly blasted the Cassidy-Graham bill this week over how it would allow states to loosen, if not end, the Affordable Care Act’s requirement blocking insurers from denying coverage to people with preexisting conditions. (Randy Holmes/ABC)

The issues around that language played large in the public consciousness this week when late-night TV host Jimmy Kimmel, whose young son needed emergency heart surgery as a newborn, delivered a trio of stinging monologues.

"This guy, Bill Cassidy, just lied right to my face," Kimmel said.

The attention his attack drew bolstered less visible but equally passionate worries among an array of groups advocating for consumers, patients with certain diseases, medical professionals and others.

“This bill would be absolutely devastating,” said Cynthia Pellegrini, senior vice president of public policy and government affairs for the March of Dimes, which works to prevent birth defects and premature births. For a woman who had a preterm baby and becomes pregnant again, the price of coverage would “simply place insurance out of reach,” Pellegrini said.

People who need blood pressure medicine to ward off strokes or heart attacks, cancer survivors and those with arthritis could similarly find health plans unaffordable — as had long been the case before the ACA became law in 2010.

The plan named for Cassidy and its other primary sponsor, Sen. Lindsey O. Graham (R-S.C.), would officially preserve the ACA’s prohibition against insurers refusing to sell coverage to customers based on their poor health. But the bill’s fine print makes that insurance guarantee hollow, critics said.

“It’s a false promise,” said Sue Nelson, the American Heart Association’s vice president of federal advocacy. “It might be there, it might not, depending on the state.”

Beyond letting insurers charge higher premiums to people with histories of medical conditions, the bill would let states unwind an ACA rule that insurers may not charge their oldest customers more than three times as much as young adults. It also would enable states to free insurers selling health plans to individuals and small businesses from covering all of the ACA’s required benefits. And insurers could return to setting yearly and lifetime limits on coverage.

States would need to ask federal health officials for permission to make such changes. McConnell and other GOP senators contend this waiver process would prevent any erosion of protections.

States “would have to do some serious explaining to the Health and Human Services secretary if they tried to get rid of that,” Sen. Joni Ernst (R-Iowa) said in a session with constituents this week in Charles City.

Yet others say the bill’s language has more loopholes than guaranteed protections. For one thing, states could get permission based simply “on their say-so,” said Karen Pollitz, a senior fellow at the Kaiser Family Foundation. There are no criteria that states would have to meet to prove that people with medical conditions would still have access to affordable coverage.

Nor would federal officials be required to check back to make sure that insurance plans were affordable.

“It’s like saying, ‘I am going to give you a chocolate chip cookie,’ but it has no chocolate chips, no sugar, no butter, no eggs. It’s not a cookie,” Pellegrini said.

A coalition of nearly two dozen patient and consumer groups, known informally as the Burrito Coalition since it formed over a Mexican breakfast, is planning a rally on Monday just before the Senate Finance Committee holds a scheduled hearing on the Cassidy-Graham measure.

On Friday, committee Democrats urged the panel’s Republican majority to move the hearing to a larger room. House Minority Leader Nancy Pelosi (D-Calif.) listed the legislation’s treatment of preexisting conditions in a letter to her chamber’s Democratic members. She urged them to “highlight the devastating costs Republicans are trying to inflict on hard-working Americans.”

Nelson, who is leading the Burrito Coalition, said its members have “had conversations with every relevant Senate office.” She remained concerned on Friday about whether their efforts were going to make a difference. “The impression I’m getting is that we are not getting through to them. They nod their heads, but it’s not really a conversation,” she said.

Sen. Cory Gardner (R-Colo.), whose state would lose billions of dollars in funding under the Cassidy-Graham bill, has not said how he will vote. In May, he detailed his test for any health-care proposal: “We need to make sure the people with preexisting conditions continue to have coverage and continue to have access to affordable coverage.”

Such promises have been a Republican mantra amid the party’s zeal to dismantle the ACA — and they have persisted in recent days even in the face of the latest GOP plan’s contradictory provisions.

Speaking in his ceremonial office in the White House on Friday, Vice President Pence said the bill “requires coverage for people with preexisting conditions.”

Pence was echoing the president, who had announced in a tweet late on Wednesday afternoon: “I would not sign Graham-Cassidy if it did not include coverage of preexisting conditions. It does.”

Alice Crites contributed to this report.