If the court strikes down the ACA, he expects the administration to release a plan supporting "generously funded state-based, high-risk pools."
Such pools existed in most states before the ACA. They helped provide coverage for people with preexisting conditions who were denied policies by insurers. But the pools were expensive, so they often were underfunded, capped members' benefits and yielded long waiting lists.
Some think the white paper is not so much a plan as a "combination of policy ideas and political statements," said Joe Antos at the conservative-leaning American Enterprise Institute.
Still, he doubts the GOP needs a comprehensive health proposal. Republicans are more likely to gain politically by merely attacking the Democrats' ideas, he said, especially if the Democratic nominee backs proposals for a fully government-funded health care system, such as the "Medicare for All" plans some candidates support.
Republicans will "have their own one-liners, saying they are dedicated to protecting people with preexisting conditions. That might be enough for a lot of people," Antos said.
Politically, it's risky. While many voters don't understand all that the ACA does, some of its rules enjoy broad support. That's particularly true of the protections for people with medical problems -- insurers are barred from rejecting them for coverage or charging them more than people without such conditions.
The Republican effort to repeal the law galvanized activists during the 2018 midterm elections and is credited with boosting Democrats to victory in many House districts.
Analysts on both sides expect concerns about health costs and the ACA to play a large role again in 2020.
For Republicans, "the risk of doing nothing potentially leaves no port in a storm if the ACA is overturned legally," said Rosen. "But a more limited version, which is what most Republicans are for, is likely to be met with the same concerns. No matter what the president says, it won't be enough for the Democrats."
Opinion poll analyst Blendon said there is an additional unknown: which Democrat will win the nomination -- and what type of coverage he or she will back.