Pete Buttigieg's healthcare plan, "Medicare for all who want it," has been trending on Twitter as he has competed closely with Bernie Sanders in the first two Democratic nomination contests.

The two contenders are likely to clash over their healthcare differences at the ninth Democratic debate in Nevada on Wednesday.

Sanders has long advocated for a “Medicare for all” plan, through which people would be enrolled in a government-run health plan and all private insurance plans would be eliminated. About 56% of people in the United States favor a “Medicare for all” system, according to Kaiser Family Foundation polling . Buttigieg’s idea, though, appeals to more centrist Democrats fearful of running too far to the left, as it would allow people to choose whether they want a government plan or to keep their private insurance.

The Sanders Plan

Sanders says too many people in the U.S., about 79 million, struggle to pay their medical bills under the current system. "Medicare for all" promises a robust set of benefits meant to eliminate all expenses for enrollees. It would cover hospital visits, primary care services, long-term care for disabled people, prescription drugs, and maternity care. It would also provide vision and dental benefits. Under his plan, the government would negotiate drug prices with pharmaceutical companies with the goal of capping prescription drug costs for people at $200 annually.

However, the plan would cost tens of trillions, which many economists say is unfeasible.

The Buttigieg Plan

Buttigieg’s “Medicare for all who want it” proposal is designed to expand healthcare access to all people while stopping short of a totally government-financed plan such as the one Sanders champions. Buttigieg wants to keep private insurance companies while giving people with private coverage the option to purchase a government health plan. Uninsured people would be automatically enrolled in the government plan, starting with those eligible for Medicaid who live in states that have not expanded Medicaid under Obamacare. Buttigieg wouldn’t get rid of premiums, but his plan would cap plan premium payments at 8.5% of a person's total income.

Though the cost of a "Medicare for all who want it" plan wouldn't cost nearly as much as Sanders's plan, Buttigieg said the government would still have to pay about $1.5 trillion over a decade.

Buttigieg's case against Sanders's "Medicare for all"

Rather than forcing all people in the U.S. onto a single government plan, Buttigieg's plan aims to preserve people's power to choose a health plan, whether through the government or a private insurer. He says he, unlike Sanders, "trusts" the people to pick the plan that's best for them, adding that the "Medicare for all who want it" proposal creates "a natural glide-path to Medicare for All."

"There is now a majority ready to act to make sure there's no such thing than an uninsured American and no such thing as an unaffordable prescription," Buttigieg said in an attack against Sanders during the Feb. 7 debate. "Just so long as we don't command people to accept a public plan if they don't want to."

Sanders has countered that putting everyone on the same government health plan is essential to cutting out premiums and co-payments, the largest factors in making healthcare unaffordable.

Buttigieg has said that the plan would cost too much money. A “Medicare for all” system could increase federal government spending by about $34 trillion over a decade, according to the Urban Institute. However, Sanders argues that a "Medicare for all" system would eliminate high administrative costs, pharmaceutical lobbying profits, and other healthcare expenses that he says are wasteful, leading to net savings.

However, Buttigieg's plan aims to encourage competition among private insurers to keep costs down and entice more people to choose a private plan over a Medicare-like plan. He has said his “Medicare for all who want it” plan would cost about $1.7 trillion — “no small fee,” but better than the alternative. For reference, the Congressional Budget Office estimated the cost of Obamacare to be about $1.76 trillion from 2012 to 2022.