Sen. Elizabeth Warren (D-Mass.) unveiled a new plan on Friday to pass major legislation expanding health care within 100 days as president and to get a Medicare for All government-run health care system enacted by her third year in office.

The proposal lays out a vision towards universal health care coverage, but one that also acknowledges the difficult political constraints standing in the way to getting it through Congress under a new Democratic administration. It would quickly put in place the building blocks of Medicare for All, which could also serve as a backup plan in case her efforts to establish a universal, government-run health care program fail.

Under the plan, Warren would use her executive authority both to drive down the price of prescription drugs (in some cases, by threatening the patents of drugmakers charging high prices) and to reverse changes implemented by President Donald Trump that have undermined the Affordable Care Acts protections for people with preexisting conditions.

But the plan also has a major legislative component, including the creation of a new, government-run insurance plan. It would be free to all children and all people with incomes less than twice the poverty line, and open to everybody else, who would pay varying, income-based premiums. By design, it would be more generous and generally cheaper than private insurance for many, and probably most, people. The same legislation would also open up the existing Medicare program to people 50 and older, while improving the financial assistance available to people buying insurance through HealthCare.gov and the state exchanges.

Such legislation would encounter stiff opposition from the same groups that would fight Medicare for All. But Warrens campaign says she plans to use a legislative process called budget reconciliation that requires only a simple majority in the Senate to make it law. Republicans recently used budget reconciliation to push through their tax cuts and attempted to used it to pass repeal of the Affordable Care Act.

By shifting millions of people to a public health care system gradually, Warren hopes her proposal will help build support for a full-fledged Medicare for All program down the line while offering people immediate health care relief in the short term.

However, its hard not to view Warrens new plan through a political lens given the tightening Democratic primary, one in which her impressive rise to the front of the pack in public opinion polls appears to have leveled off less than three months from the Iowa caucuses.

By delaying the elimination of private health insurance under Medicare for All until later in her presidency, Warren is attempting to blunt attacks from moderate rivals for the Democratic presidential nomination, as well as inoculate herself against a Republican onslaught during a general election campaign against Trump. The delayed timeline, meanwhile, would also give Democrats who are uncomfortable with Medicare for All and its elimination of private insurance an opportunity to get on board with her candidacy.

The new plan may open her to criticism from Medicare for All supporters, as well. Fellow 2020 contender Sen. Bernie Sanders (I-Vt.), for example, has not said he will wait as long as three years to pass his Medicare for All proposal, creating some daylight between the two progressive senators ahead of next weeks presidential debate in Georgia.

The three-year timeline, meanwhile, could be fraught with political risk. There are many political variables to consider alongside Warrens plan to wait until after the 2022 midterm elections to pass Medicare for All, but the Senate map in 2022 looks better for Democrats than the one next year, which could boost Warrens prospects of getting the program passed. But if the party fails to capture the upper chamber in 2020, a difficult task, it would make much of these calculations moot altogether.

Finally, Warrens reliance on budget reconciliation to pass a public health insurance option acknowledges the difficulties in eliminating the filibuster, which she has called for if Democrats win the Senate next year. If it were easy to convince her Democratic colleagues to get rid of the long-standing 60-vote supermajority requirement, her plan wouldnt require budget reconciliation at all.

But red-state Democratic Sens. Joe Manchin of West Virginia, Jon Tester of Montana, and Kyrsten Sinema of Arizona, for example, recently ruled out ever supporting eliminating the filibuster. And theyre not alone .

Jonathan Cohn contributed to this report.