Prognostication is the province of the bold. After all, the American Health Care Act (AHCA) seemed dead as a doornail right up until the House of Representatives passed it on a 217-213 vote last month following an initial failure. But just three Republican defections in the Senate would be enough to sink the whole effort. Here’s what we know about the bill—and what lawmakers are saying about it—so far.

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The rift between conservatives and moderates still matters.

Much of the focus on the Senate’s uniquely secretive talks on the health care legislation has focused on whether or not it can muster up the requisite support from the chamber’s moderates, like Sens. Lisa Murkowski, Susan Collins, and others, while holding on to right wing conservatives such as Kentucky Sen. Rand Paul, Utah’s Mike Lee, Texas’ Ted Cruz, and Wisconsin’s Ron Johnson.

That latter group threw out an early gauntlet on Thursday.

Today I join senators Lee, Johnson, and Cruz in opposition to the #HealthcareBill. Read here: https://t.co/vo6lvirree pic.twitter.com/FF9ChIBaBA

— Rand Paul (@RandPaul) June 22, 2017

But it’s an open question whether or not this is simply political posturing or a red line. The Senators’ language implies there’s plenty of room to maneuver; however, that raises a whole host of other issues for GOP moderates who have previously sounded skepticism about deep cuts to the Medicaid program which serves as a health safety net for the poor.

Those Senators also have several provisions they may hang their hats on in the BCRA. For instance, the bill shifts its focus from age to income when it comes to health insurance premium assistance. But some other factors may be less palatable from a political perspectives.

A massive wealth transfer to the rich.

One of the AHCA’s biggest criticisms was that it rolled back assistance to the poor, the elderly, and the sick in exchange for huge tax breaks for wealthy people. At first glance, the BCRA appears to take the same tact, taking a buzzsaw to Medicaid (Obamacare’s expansion of that program would be phased out and it would be fundamentally restructured by its first-ever spending cap) and eliminating the subsidies available to people making four times the poverty level. There’s also a rather broad waiver program which some experts say would allow states to opt out of many Obamacare protections for people with high health care costs.

And then there’s the PR. Critics are already lambasting the bill for one specific measure that would allow insurance companies to deduct CEO salaries exceeding $500,000 while making its various safety net cuts.

Former President Barack Obama felt strongly enough about some of these issues to release a public statement on Facebook decrying the legislation.

We still don’t know how the industry will react.

I’ve personally reached out to some of the nation’s largest medical trade groups–including the AARP and the American Medical Association—to ask for their takes on the legislation. Most have said they’re still reading through it. But the industry was strikingly united in its opposition to the AHCA. Hospitals, doctors, and patient advocates alike said that it would lead to massive coverage losses (a claim echoed by the independent Congressional Budget Office) which, in turn, would be very bad for business. The Senate’s bill may contain some sweeteners compared to the House’s effort. But it could still be a hard pill to swallow.

Senate leaders reportedly want to vote on this legislation as soon as next week.