The headlines about presidential candidate Joe Biden’s new health care plan called it “a nod to the past” and “Affordable Care Act 2.0.” That mostly refers to the fact that the former vice president has specifically repudiated many of his Democratic rivals’ calls for a “Medicare for All” system and instead sought to build his plan on the ACA’s framework.

Sen. Bernie Sanders, one of Biden’s opponents in the primary race and the key proponent of the Medicare for All option, has criticized Biden’s proposal, complaining that it is just “tinkering around the edges” of a broken health care system.

Still, the proposal put forward by Biden last week is much more ambitious than Obamacare — and, despite its incremental label, would make some very controversial changes. “I would call it radically incremental,” said Chris Jennings, a political health strategist who worked for Presidents Bill Clinton and Barack Obama and who has consulted with several of the current Democratic candidates.

Republicans who object to other candidates’ Medicare for All plans find Biden’s alternative just as displeasing.

“No matter how much Biden wants to draw distinctions between his proposals and single payer, his plan looks suspiciously like “SandersCare Lite,” wrote former congressional aide and conservative commentator Chris Jacobs.

Biden’s plan is built on expanding the ACA to reduce costs for patients and consumers, similar to what Hillary Clinton campaigned on in 2016. It would do things Democrats have called for repeatedly since the ACA was passed. Among them is a provision to that would “uncap” federal help to pay for health insurance premiums — assistance that is now available only to those with incomes below 400% of the poverty level, or about $50,000 for an individual. Under Biden’s plan, no one would be required to pay more than 8.5% of their income toward health insurance premiums. The plan also proposes to make coverage more affordable to use by effectively lowering deductibles and copayments.

But it includes several proposals that Congress has failed repeatedly to enact, including some that were part of the original debate over the ACA. It also has some initiatives that are so expansive, it is hard to imagine them passing Congress — even if Democrats sweep the presidency and both chambers of Congress in 2020.

Here are some of the more controversial pieces of the Biden health plan:

Public Option

Although many of the Democratic presidential candidates have expressed varying degrees of support for a Medicare for All plan, nearly all have also endorsed creating a government-sponsored health plan, known colloquially as a “public option,” that would be available to people why buy their own health insurance. In other words, it would apply to those who don’t get insurance through their job or qualify for other government programs, like Medicare or Medicaid.

A public option was included in the version of the ACA that passed the House in 2009. But it could not muster the 60 votes needed to pass the Senate over GOP objections — even though the Democrats had 60 votes at the time.

Biden’s public option, however, would be available to many more people than the 20 million or so in the current individual insurance market. According to the document put out by the campaign, it would be available to those who don’t like or can’t afford their employer insurance, and to small businesses.

Most controversial, though, is that the 2.5 million people ineligible for either Medicaid or private insurance subsidies because their states have chosen not to expand Medicaid would be automatically enrolled in the new public option, at no cost to them or the states where they live. Also included automatically in the public option would be another 2 million people with low incomes who currently are eligible for ACA coverage subsidies but would also be eligible for expanded Medicaid.

That part of Biden’s proposal has prompted charges that the 14 states that have so far chosen not to expand Medicaid would save money compared with those that have expanded, because expansion states have to pay 10% of the cost of that new population.

Jennings, the Democratic health strategist, argued that’s unavoidable because it’s the population that needs coverage most. “If you’re not going to have everyone get a plan right away, you need to make sure those who are most vulnerable do,” he said.

Abortion

The Biden plan calls for eliminating the “Hyde Amendment,” an annual rider to the spending bill for the Department of Health and Human Services that forbids the use of federal funds to pay for abortions. Biden recently ran into some difficulty when his position on Hyde was unclear.

But the plan also calls for federal abortion funding. “[T]he public option will cover contraception and a woman’s constitutional right to choose,” said the document.

In 2010, the Affordable Care Act very nearly failed to become law after an intraparty fight between Democrats who supported and opposed abortion funding. Abortion opponents wanted firm guarantees in permanent law that no federal funds would ever be used for abortion; abortion-rights supporters called that a deal breaker. Eventually, a shaky compromise was reached.

And while it is true that there are now far fewer Democrats who oppose abortion in Congress than there were in 2010, the idea of even a Democratic-controlled Congress voting for federal abortion funding seems far-fetched. The current Democratic-led House has declined even to include a repeal of the Hyde Amendment in this year’s HHS spending bill, because it could not get through the GOP-controlled Senate or get signed by President Donald Trump.

Undocumented Immigrants

When Obama said in a speech to Congress in September 2009 that people not in the U.S. legally would be ineligible for federal help purchasing insurance, it prompted the infamous “You lie!” shout from Rep. Joe Wilson (R-S.C.).

Today, all the Democratic candidates say they would provide coverage to undocumented residents. There is no mention of them specifically in the plan posted on Biden’s website, although a campaign official told Politico that undocumented people would be able to purchase plans on the health insurance exchanges but would not qualify for subsidies.

Still, in his speech unveiling the plan at an AARP-sponsored candidate forum in Iowa, Biden did not address this issue of immigrants’ health care. He said only that his plan would expand funding for community health centers, which serve patients regardless of ability to pay or immigration status, and that people here without legal authority would be able to obtain coverage in emergencies, which is already law.