The gravity of how difficult it will be to fully repeal and replace Obamacare is settling in on Capitol Hill.

Republican senators who spent years railing against the president’s signature health care law are now trying to find consensus on how they want to make good on their years-long campaign promise to dismantle it – and the growing consensus is that it is going to take time to find a replacement.

“Its gonna take us awhile to make that transition from the repeal to actually replacing it with more affordable health coverage, which provides people better access,” Sen. John Cornyn (R-TX), the Senate majority whip, told reporters Tuesday. “There is a lot to do so it’s not going to happen overnight.”

Republicans’ inability to coalesce around a replacement plan in the six years after Obamacare was passed means they have no easy alternative to queue up with a repeal, which they have vowed to make the top of their agenda next year. Their current inability to settle on a clear repeal and replace plan also reflects the trade-offs that have been dogging the GOP in last half-decade. Within the Republican caucus are deep, philosophical rifts over basic questions about health care policy and the government’s role in providing access to coverage.

Lobbing critiques at rising premiums while on the campaign trail was far easier than what comes next as Republican confront the reality that along with their much bemoaned individual mandate, fully repealing Obamacare also would mean unraveling popular provisions and benefits that have become available under the law and expanded health care coverage.

Rank and file Republicans Tuesday voiced an array of concerns about what moving too fast could mean for millions of individuals who had attained health care coverage through expanded Medicaid programs in the states and about what would happen to individuals with pre-existing conditions, who under the ACA were able to obtain health insurance. Instead of repealing and replacing Obamacare suddenly, Republicans in the Senate are now discussing a way to “transition” from Obamacare to their alternative, which is still to be determined.

Senators stressed Tuesday that they were leaning toward a process that gave Republicans the opportunity to repeal Obamacare now and then spend an undefined amount of time working on a replacement.

“I’m from a state that has an expanded Medicaid population that I am very concerned about,” said Sen. Shelley Moore Capito (R-WV). “I don’t want to throw them off into the cold, and I don’t think that’s a strategy that I want to see. It’s too many people. That’s over 200,000 people in my state. So we need a transition. I think we’ll repeal and then we’ll work during the transition period for the replacement vehicle.”

Capito said she would support a plan to that would leave a two- to three-year transition period.

Slowly replacing Obamacare is likely to irritate conservatives who had hoped Republicans would act fast to gut Obamacare, but it echoes what Sen. Lamar Alexander (R-TN), the chair of the Health, Education, Labor and Pensions Committee, signaled before the Thanksgiving break when he told reporters it might take years to fully repeal and replace the Affordable Care Act.

“There are contracts out there that insurers have so I think we all know on Day 1 it’s not going to be repeal and replace,” Sen. Jeff Flake (R-AZ) told reporters Tuesday.

Sen. Roger Wicker (R-MS), the outgoing chair of the National Republican Senatorial Committee, was among the Republicans floating a repeal-and-delay plan, which health policy experts warn could still cause major chaos in the insurance market.

“We can use reconciliation,” Wicker told TPM, referring to the legislative maneuver that would allow Republicans to dismantle some ACA provisions with only a majority vote. “I do think there will be two- or three-year phase in about the replacement.”

Not only are Republicans recognizing that fully repealing Obamacare presents a host of legislative and policy hurdles, there are provisions in the law – such as protections for individuals with pre-existing conditions – that are so popular that Republicans could pay a political cost for repealing them.

President-elect Trump has signaled that he wants those components intact, but that also presents a challenge. If Republicans want to make good on their promise to repeal the individual mandate as well as maintain their vows to to protect individuals with pre-existing conditions, then how can they guarantee insurers won’t hike premiums drastically or drop out of the individual market altogether if they’re forced to cover a sicker, more costly risk pool. The answer is Republicans aren’t entirely sure yet.

“Once you say that everybody should be covered, can’t be denied coverage because they are sick – which most Americans would agree with that – you put yourself in a box. Insurance is about young people who are healthy buying insurance like you all to pay for me and him,” Sen. Lindsey Graham (R-SC) said, pointing to the oldest reporter in the scrum. “If you don’t have to buy insurance until you get sick, most people won’t. That’s where the mandate becomes important.”

Graham added: “Somebody’s got to work through this problem. If we’re going to accept the proposition that you can never be denied coverage because you’ve been sick, then somebody’s got to create a system where people participate.”

Senate Majority Leader Mitch McConnell (R-KY) remained vague at his press conference on Tuesday about the order and timing for the plan.

“What we intend to do is go forward with a process after the first of the year and begin the opportunity to repeal and replace, so that will start shortly after we reconvene, after the swearing in,” McConnell said.

Sen. John Barrasso (R-WY), a member of the GOP Senate leadership team, told reporters that Republicans plan on replacing the law in a “piece by piece way.”

“We’ll be starting in January with budget reconciliation to get something on then-President Trump’s desk,” Barrasso said, while arguing Republicans would be wary of pushing any major bills to replace it right off the bat.

“[Democrats] messed it up thoroughly over six years and there’s not a quick 2,000-page replacement,” Barrasso said. “It’s an ongoing process. It’s going to transition and take a number of years to do that.”

