Medicaid expansion in Capito’s state — which voted for Trump overwhelmingly — was implemented by Democratic Gov. Earl Ray Tomblin in 2013 without the approval of its legislature. Other GOP senators live in purple states where Democratic state legislatures expanded Medicaid, while the states of some members — like Iowa Sens. Joni Ernst (R) and Chuck Grassley (R) — only expanded Medicaid once their Republican governors were able to work out a deal with the Obama administration to expand in a moderated form.

“A number of us have been talking about that you want to make sure that any repairing and fixing — because it clearly needs repairing and fixing — that we do now takes into account the current situation with different states that have taken different actions. Indiana’s expansion was different from ours, was different from Ohio’s. … It’s a topic that a lot of us were focused on it,” said Sen. Dan Sullivan (R-AK).

Only two of the Republican senators from expansion states will be up for reelection in 2018.

The expanded Medicaid program in the Affordable Care Act raised the eligibility level for low income adults earning up to 138 percent of the federal poverty line. The idea was that the expansion would cover the gap between low income adults enrolled in the traditional Medicaid program and those consumers who can afford subsidized insurance on the Obamacare exchanges.

The program is set up so that the federal government covers 100 percent of the expansion for the first three years, and then 90 percent beyond that. Some Republicans argue that states shouldn’t be expected to pick up that portion of the bill and the program was challenged in the Supreme Court, where a conservative majority ruled that states could have the choice whether to expand Medicare.

Many GOP lawmakers are leaning towards an Obamacare repeal plan that would give them a sunset period during which to cobble together a replacement. Health policy experts warn that this approach can still cause chaos in the near-term.

Republicans about a year ago passed a bill to repeal parts of Obamacare that many GOP lawmakers have said will be the model of their repeal effort early next year. That version — which was ultimately vetoed by President Obama –delayed the repeal of Medicaid expansion by two years, and the legislation being considered now may delay it by three, according to some members.

“Last time, it was a two-year transition period, so people who are currently covered by Medicaid because of the Affordable Care would know that the rug is not going to be pulled out from under them,” Sen. Rob Portman (R-OH) told TPM this week. “John Kasich, our Republican governor, who was for having expanded Medicaid, liked that because it gives him a chance to weigh in on the kind of Medicaid that he would like to see, which would be to give the state much more flexibility.”

Portman added that “the idea is to not end the expansion, but to give the states the tools to be able to cover more people more effectively.”

Such an approach may not be as simple as Portman makes it sound considering that Democrats are already balking at the idea that they would help Republicans replace Obamacare, which will likely require 60 votes, by the time the repeal goes into effect in two or three years. And some Republicans have objected to the idea of Medicaid expansion altogether.

The disagreement over whether to maintain Medicaid expansion popped up in the debate over the 2015 repeal legislation, where the program was preserved in the House version. Under pressure from conservatives, the Senate added the delayed-repeal of the program.

Correction: A previous version of this story mistakenly described the Medicaid eligibility rate of the traditional program as being at 100 percent of the federal poverty line. Medicaid eligibility varied from state to state before the ACA, and continues to vary in non-expansion states. We regret the error.