WASHINGTON -- Policy scholars vigorously debated the best pathway to repealing and replacing the Affordable Care Act during a briefing hosted by the American Enterprise Institute (AEI) on Friday.

Panelists were asked what specific elements should be included in a replacement plan and how Congress should implement such a plan.

Some panelists argued for a two-step process, repeal then replace; whereas more liberal academics warned that not enacting both steps at once would destabilize an already shaky insurance market.

In picturing the situation the new administration will encounter this January, John McDonough, PhD, MPA, professor at the Harvard T.H. Chan School of Public Policy in Boston, compared it to a scene from the original "Ghostbusters" movie.

In it, a lawyer for the Environmental Protection Agency is about to burst open a storage facility containing all the mischievous and malevolent spirits the heroes have rounded up.

"You really don't want to do this. You don't know what's going to happen," McDonough said. "And quite literally all hell breaks loose," he said.

In his view, a Republican administration and Congress are wholly unprepared for the the consequences of their actions.

But the AEI's Joseph Antos, PhD, who also served as moderator, emphasized that the GOP-led Congress and incoming administration, despite criticism to the contrary, are indeed prepared and have concrete ideas for how to replace the Affordable Care Act.

Thomas Miller, JD, a resident fellow at AEI, likened Obamacare to Howard Hughes's "Spruce Goose," the largest wooden airplane ever built -- something "too big and unwieldy to land," while the alternative plans were a "stripped-down" plane, both small and nimble. All that's needed is a runway, he said.

While defining the ideal replacement plan as shiny, new and better, Miller also acknowledged there are still challenges -- not least being the lack of consensus among Republicans in Congress.

Challenges Ahead

And despite his starkly different portrayals of Obamacare and its replacement plan, Miller was cognizant of the obstacles to replacement:

The Senate and House have clashed on timing of repeal

The Congressional Budget Office must score whatever final plan is produced

Republicans can't pass a replacement without some Democrats to help

While the GOP has enough votes on its own to partially repeal the law through the budget reconciliation process, which cannot be filibustered, to pass a replacement bill they will need at least eight Democratic votes in the Senate.

Antos and another panelist Steve Harrington, PhD, a professor at the Wharton School at the University of Pennsylvania in Philadelphia, highlighted the key themes of current replacement plans, including House Speaker Paul Ryan's (R-Wis.) "A Better Way" and Rep. Tom Price's (R-Ga.) separate "Empowering Patients First Act" as well as AEI's own white paper, these include:

Replacing the income-based subsidy with a refundable tax credit

Eliminating the mandate while offering incentives to get coverage

Using one or more high risk pools to help manage adverse selection

Shifting regulatory authority for insurance back to the states

Each of these plans would repeal the Affordable Care Act and put in place a policy that's more market-driven and consumer-oriented, he noted. Still he acknowledged that Congress hasn't agreed upon the mechanics of a single plan and that "the specifics matter."

Nuts and Bolts

One of the panel's goals was to clarify the more granular details of replacement. Harrington suggested that state high-risk pools could protect the sickest of beneficiaries from falling through the cracks. The federal government would need to provide money for those pools, he noted.

Harrington argued that de-linking tax credits from income could create a simpler method of subsidizing insurance. Since older people generally are less healthy than younger individuals the tax credits could increase with age. He also said that keeping the popular pre-existing conditions clause would be feasible if individuals maintained coverage.

But Harrington also acknowledged the possibility of "significant instability" during the repeal and replacement process. He noted that while risk corridors -- a mechanism for the federal government to helping those insurance companies with the most expensive claims -- are unpopular with conservatives, "some stability mechanism would be desirable," he said.

Not So Simple

A more liberal panelist, Robert Reischauer, PhD, a fellow at the Urban Institute, agreed that some reinforcement would be needed to keep the insurance markets stable during a transition.

He suggested that individuals would find the proposed age-related tax credits "pretty skimpy" compared to the current premium subsidies. He also noted that while critics blasted the so-called Cadillac tax, the Republicans idea of a limit on deductibility for employer-sponsored insurance, would likely be as unpalatable.

"When you go down to the details, the [regulations] and the rules for what they're proposing are equally problematic," Reischauer told MedPage Today.

And one panelist, James Wallner of the conservative Heritage Foundation, urged that repeal would need to happen in advance of a replacement, mostly as theater -- because doing both at once looks too much like amending the law, which would be anathema to many on the right.

Rather than rely on the Republicans to forge a sense of unity, which isn't real, Waller said the goal will be "repeal everything you can now," and then debate the kind of healthcare system people want.

There is one thing that both liberals and conservatives can likely agree on and that is how high the stakes are for Republicans.

With a majority in both chambers and a Republican president, Wallner said, "There are no more excuses."