As President Trump said after only a month or so in office, “Nobody knew health care could be so complicated.”

It’s likely Senate Republican leaders knew — but now they are living and breathing its complexity as they tinker with their proposed bill and await yet another assessment from the Congressional Budget Office on its estimated costs.

Their challenge is to balance the interests of their party’s moderate and most conservative members, and to avoid stripping the Affordable Care Act of its most popular features — especially protections for people with preexisting conditions. Their goal is to get at least 50 votes — with one more from Vice President Mike Pence, if necessary, to break a tie.

What are the key sticking points? Who are the potentially pivotal votes? Julie Rovner of Kaiser Health News, Joanne Kenen of Politico, Margot Sanger-Katz of The New York Times and Paige Winfield Cunningham of The Washington Post discuss these questions and more, in a roundtable on why it is so difficult to make changes in a law the Republicans have been seeking to repeal since its inception.

The transcript below has been edited for length and clarity.

Julie Rovner: Paige, what are you hearing about how Senate Republicans are trying to change their bill to win a majority vote when they come back to Washington next week?

Paige Winfield Cunningham: [Senate Majority Leader Mitch] McConnell shipped off [to the Congressional Budget Office for scoring] about five to seven changes — potential changes — to this legislation at the end of last week. There’s a couple of things in there that could appeal to conservatives. A couple of things that could appeal to moderates, and he sees these as … levers he could pull to get that pathway to 50 votes.

Rovner: And what’s an example?

Winfield Cunningham: The thing that the conservatives are really pushing for is this amendment from Ted Cruz, which would basically expand the opt-out for insurers for more of the ACA regulations, including potentially the protections for people with preexisting conditions. Another change that McConnell’s looking at is an expansion of the use of health savings accounts, possibly allowing people to pay their premiums with those accounts.

Rovner: Which you can’t do now.

Winfield Cunningham: Which you can’t do now, correct. And there are a couple of changes that the CBO is also scoring that could help to bring the moderates onboard. There’s talk of adding on more opioid funding.

Rovner: Now Margo, you wrote about this amendment from Texas Republican Ted Cruz. … Tell us a little bit about this amendment and what it would do.

Margot Sanger-Katz: He’s trying to find a compromise so that he can preserve a lot of the consumer protections that moderates are really concerned about keeping but also allow less regulation of insurance products, which I think is important to conservatives who think there needs to be more of a free market for insurance plan design. So what his proposal says is that any insurer that wants to sell health insurance to individuals needs to have one plan that fulfills all of the Obamacare rules and then they can offer basically whatever else they want. And so the idea is that if you’re the kind of customer who wants a plan with all the rules that you know protect preexisting conditions, that covers the wide array of benefits that are required by Obamacare and all of the other regulations, you could buy that plan. If you want to buy, like, a super high-deductible plan that only covers hospital care, you could buy that plan if it’s on the market.

Rovner: And presumably that would have a much lower premium.

Sanger-Katz: Presumably it would have a much lower premium. I mean, if you talk to experts in insurance markets, what they say is what this really does is it kind of splits the market in half. So you end up with people who are relatively high-income and especially people who are relatively healthy, they’re going to buy the skimpy hospital-care only sorts of plans. And then people who are low-income and need subsidies or people who have health conditions — you know, if you’re someone who has HIV, if you’re someone who has multiple sclerosis or cancer or some kind of chronic disease — you really probably need a plan that covers everything. Those people probably are going to buy the Obamacare-compliant plans, and the result is that the plans that follow all the rules will tend to be really, really expensive, and the plans that don’t are going to be, you know, comparatively much cheaper. And so it creates some problems. But it’s interesting because the compliant plans would be eligible for subsidies.

Rovner: And I know that’s been mentioned by a lot of people who were concerned that those people who do earn too much … to get the help from the federal government would be exposed to those premiums. But also wouldn’t that raise the cost for the federal government because the premiums would go way up? The individuals wouldn’t pay them, but the federal government would.

Sanger-Katz: Yeah. I think that’s one of the interesting questions that CBO is probably dealing with right now.

Rovner: So Joanne, … members of the Senate have gone home this week. It’s the 4th of July. Normally this would be a week where you’d see a lot of town hall meetings a lot of events, a lot of picnics and stuff. That’s not really been the case this time has it?

Joanne Kenen: There are very few town halls this week. … Sen. Cruz, he didn’t have a formal town hall, but he’s had public appearances. You know he is not shy about his opinions. He’s mixed it up with liberals who have come to protest. But you know he’s not a bellwether. We know where he is. Dean Heller from Nevada is very, very, very interesting. … He may turn out to be the pivotal vote in this debate. … He’s a moderate Republican who’s come out against the bill. Nevada has a Republican governor, [Brian] Sandoval, who has also been implementing the bill … one of the two or three Republican governors has pretty much embraced it. … Heller did have a town hall. He had it in a very rural part of Nevada. Nevada does have some problems with Obamacare. There are some bare counties that don’t have coverage, some rural counties. And you know, it wasn’t a fireworks thing, but it was interesting that he was out there. And Susan Collins [of Maine] … she’s another independent-minded moderate, and she doesn’t like this bill. And the people came out there to support her opposition to it.

Sanger-Katz: Joanne, one thing that was interesting to me when Sen. [Jerry] Moran [of Kansas] came out with his opposition to the bill. I called someone who knew Kansas politics and I said, “Oh, like he wasn’t on my radar.”

Kenen: No, he wasn’t on anyone’s radar.

Sanger-Katz: And they pointed out to me that he had done a town hall meeting at 7:30 in the morning on a Monday before coming back to Washington. And I think this was an attempt to try to, like, keep it quiet, you know. And there was all this local news coverage of video of people just hammering him. And I think, you know, it may have sat with him during the couple of weeks between that event and when it came time for him to speak out about the bill.

Kenen: Because when voters come out at 7:30 in the morning to yell at you, it is a signal that there is something going on.

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This story was produced by Kaiser Health News, an editorially independent program of the Kaiser Family Foundation.