The bill now lets insurers offer any plan they want as long as they provide one gold and one silver option that complies with former President Barack Obama's Affordable Care Act (including coverage for pre-existing conditions and preventive care). It also allows individuals to use their health savings accounts to pay for premiums, another provision Lee had hinged his support on.
"The new Senate bill is substantially different from the version released last month and it is unclear to me whether it has improved," the senator said in a statement, noting that he'll take time to study the draft.
Even with Lee's potential support, the bill's success is in doubt. While Cruz has backed the measure, two moderate Republicans, Sen. Susan Collins of Maine and Sen. Rob Portman of Ohio, as well as conservative Sen. Rand Paul of Kentucky, have indicated their intentions to block the measure from going forward.
A handful of GOP lawmakers remain undecided and a few are opposed to a procedural motion to move the bill to debate. The divide continued Thursday with Sen. Lindsey Graham of South Carolina and Sen. Bill Cassidy of Louisiana proposing their own version of an Obamacare replacement plan that would direct funding to states.
Party leadership cannot afford to lose more than two of the 52 Republican senators, because all of the Democrats have vowed to oppose the bill.
Though he called the latest version "far from perfect" and vaguely referenced things he "would do very differently" given the chance, Utah Sen. Orrin Hatch urged his colleagues to at least debate the bill on the Senate floor.
As chairman of the Senate Finance Committee, Hatch and his staff played a key role in rewriting the legislation.
If the newest rendition doesn't pass, he said, "there is no magic elixir or silver bullet."
Meanwhile, the Congressional Budget Office is set to offer financial estimates on two versions of the bill: one that includes the Lee-Cruz text and one that doesn't, according to senior Senate policy staffers. Both analyses should be available earlier next week before an expected vote.
Lee believes his amendment would reduce costs for healthy, middle-class families the overall goal of the Senate bill. With a freer market and fewer regulations, he said during an online town hall Wednesday night, insurance companies could offer cheaper, skimpier plans to those who need less coverage. That would result in more choices for consumers.
But it could also raise costs for sick and older individuals, according to policy experts and insurance lobbying groups.
Because premiums are calculated within risk pools, those with pre-existing conditions might flock to the one Obamacare-compliant plan the insurer would be required to offer. That would likely drive up costs for that group while healthy, young individuals opt for the less expensive, less regulated options.