The Affordable Care Act is a small part of the broader American health system. In a nation of more than 320 million people, 24 million to 30 million are covered under the law, both through its marketplaces and expansion of Medicaid. That’s less than a tenth of all Americans. Most Americans who have insurance are covered through their employers, and that system did not change much under the ACA and would remain largely the same under the GOP bill to replace the ACA.

If you view the ACA, aka Obamacare, as a health care bill that changed coverage for a relatively small share of Americans, the intense debate over it during the last seven years — culminating with a renewed GOP push to repeal it — may seem disproportionate. Why have the Republicans, holding control of both houses of Congress and the presidency for the first time since 2006, made rolling back Obamacare the party’s first big legislative priority? And why have left-leaning groups organized events across the country to defend the ACA the last few weeks, instead of focusing their attention on, say, stopping Neil Gorsuch, President Trump’s Supreme Court nominee, who is positioned to block liberal goals for decades if he is confirmed?

Because the Obamacare debate is really about much more than health care. In many ways, the two parties, while focusing on the technical details of health care, are also debating fundamental questions about the role of government, work, income redistribution, race, class and Barack Obama. This is not just a debate about health care premiums or your ability to choose your doctor, no matter how often Nancy Pelosi or Paul Ryan talks about those things. Health care, more than almost any other issue, hinges on real, deep values and ideals that divide the two parties in Washington and, more importantly, Blue America and Red America.

The Affordable Care Act is the kind of policy that unites Democrats and animates the party.

Democratic voters overwhelmingly believe that the rich aren’t taxed enough and that the government should tax them more to redistribute some of the wealth of higher-income people. Obamacare takes money from upper-income Americans, adding two taxes on people with incomes above $200,000 a year. It uses those taxes (and other federal dollars) to fund tax credits that are more generous to people with lower incomes.

Democratic voters are passionate about reducing racial and income inequality, and Obamacare — through its subsidies and Medicaid expansion — disproportionately benefits people who are poor, black and Latino, because they are more likely to be uninsured than whites and upper-income people.

Democrats are a racially diverse coalition (exit polls suggest that about 45 percent of Clinton voters in 2016 were nonwhite), and there are conflicts between those in the party who say it caters too much to ethnic minorities and ignores whites and those who say it takes nonwhite votes for granted. Obamacare helps low-income whites and low-income people of color. It has, for example, dramatically reduced the number of uninsured people in Kentucky, which has a higher percentage of whites than the U.S. overall. It has also cut the number of uninsured people in ethnically diverse California.

Finally, the law is known as Obamacare, linking it closely to the man Democrats rank as their favorite modern Democratic president. And Obamacare builds on a tradition of entitlement programs enacted by Democratic presidents that include Social Security, Medicaid and Medicare, and the state Children’s Health Insurance Program.

Obamacare is the exact kind of program Republicans hate.

Republicans have long opposed creating new federal entitlements. Ronald Reagan, before he formally entered politics, was an influential voice in the 1960s opposing the creation of Medicare. Obamacare entitles nearly all low-income adults to inexpensive, government-funded health insurance if their state expands Medicaid. The law has helped put an estimated 17 million people on Medicaid, either those who enrolled in the expansion of the program through Obamacare or who were already eligible but enrolled with the increased attention and outreach efforts over the last several years.

Obamacare essentially says you can stay on Medicaid as long as your income is below a certain threshold. Republicans argue that this approach keeps people dependent on government help. Obamacare provides a disincentive to work or get a higher-paying job, Republicans say, because its subsidies for marketplace insurance are reduced as your income increases. House Speaker Paul Ryan consistently criticizes anti-poverty programs that are set up this way.

In interviews, conservative-leaning voters will tell reporters (see here and here) that they think people on Medicaid are freeloaders. Talking about Obamacare also seems to trigger some conservative voters’ stereotypes about black people getting government benefits that they don’t deserve.

But it’s not just about entitlements; Obamacare is full of tax increases, including what the Supreme Court defined as a tax on individuals who do not buy insurance. Opposition to higher taxes may be the defining feature and central source of agreement of the modern Republican Party, and many Republican members of Congress have signed a pledge not to vote for tax increases.

Finally, Obamacare was the brainchild of a man who was opposed by Republicans more intensely than any other modern president. Trump’s comments about health care, from his initial promises to cover everyone to his recent admission that he didn’t realize how complicated health care reform is, suggest that he’s less interested in the details of health care policy and more determined to get rid of a law that bears a political rival’s moniker.

In other words, if you love Obama and think Republicans are mean and kind of racist (as some liberals do), the Obamacare fight is a debate for you. (Remember when Clinton called some Trump supporters “racist, sexist, homophobic, xenophobic, Islamophobic”?)

If you hate Obama and think Democrats give money to freeloaders who want to sit on their couches and collect government benefits (as some prominent conservatives have all but said), the Obamacare fight is a debate for you. (After his defeat in the 2012 election, Mitt Romney said in a private phone call with donors that Democratic-leaning voters like “gifts” from the government, such as free health care.)

That’s why health care, more than other hot-button issues, is so polarizing:

You don’t need to understand risk corridors, reinsurance or the woodwork effect to have a rooting interest in the battle.

In short, Obamacare is a fight about health care. But it’s a fight about nearly everything else in politics, too.