Barack Obama is officially one of the most consequential presidents in American history

After Thursday's Supreme Court ruling, there's no longer any doubt: Barack Obama is one of the most consequential presidents in American history — and he will be a particularly towering figure in the history of American progressivism.

National health insurance has been the single defining goal of American progressivism for more than a century. There have been other struggles, of course: for equality for women, African-Americans, and LGBT people; for environmental protection; against militarism in Southeast Asia and the Middle East. But ever since its inclusion in Teddy Roosevelt's 1912Bull Moose platform, a federally guaranteed right to health coverage has been the one economic and social policy demand that loomed over all others. It was the big gap between our welfare state and those of our peers in Europe, Canada, Australia, New Zealand, and Japan.

And for more than a century, efforts to achieve national health insurance failed. Roosevelt's third-party run came up short. His Progressive allies, despite support from the American Medical Association, failed to pass a bill in the 1910s. FDR declined toinclude health insurance in the Social Security Act, fearing it would sink the whole program, and the Wagner Act, his second attempt, ended in failure too. Harry Truman included a single-payer plan open to all Americans in his Fair Deal set of proposals, but it went nowhere. LBJ got Medicare and Medicaid done after JFK utterly failed, but both programs targeted limited groups.

Richard Nixon proposed a universal health-care plan remarkably similar to Obamacare that was killed when then–Sen. Ted Kennedy (D-MA) walked away from a deal to pass it, in what Kennedy would later call his greatest regret as a senator. Jimmy Carterendorsed single-payer on the campaign trail, but despite having a Democratic supermajority in Congress did nothing to pass it. And the failure of Bill Clinton's health-care plan is the stuff of legend.

What Obamacare achieved

Obama signs Obamacare into law. (Pete Souza)

Then, on March 23, 2010, President Obama signed the Affordable Care Act into law. It wasn't perfect by any means. It wasn't single-payer; it lacked a public option, or all-payer rate-setting. And it still left many uninsured. But it established, for the first time in history, that it was the responsibility of the United States government to provide health insurance to nearly all Americans, and it expanded Medicaid and offered hundreds of billions of dollars in insurance subsidies to fulfill that responsibility.

In an email, UC Berkeley's Paul Pierson likened the law to a "starter home" to be expanded later on, much as Social Security — which initially had no disability benefits, left out surviving dependents and widows, and excluded (largely black) agricultural and home workers — was.

Brian Steensland, a sociologist who studies American social policy at Indiana University in Indianapolis, agrees. "The main thing it does, I think, is establish the expectation in the public’s mind that access to basic health care is a right. It’s going to be hard to go back to a time when access to health insurance, and the subsidies to help pay for it, wasn’t near-universal."

To pay for it all, the Affordable Care Act cut back on Medicare spending and hiked up taxes on rich people's investment income and health plans. It effected a massive downward redistribution of income. It's one of the most startlingly progressive laws this country has ever enacted.

And it was passed with more opposition than the social insurance programs it followed. "FDR and LBJ had lots of fellow Democrats in Congress when they pushed for the New Deal and Great Society," College of William and Mary political scientist Chris Howard says. "Their opponents, in and out of government, were not nearly as ideological or hostile as the ones facing Obama. The fact that the ACA exists at all is pretty remarkable."

"OBAMA IS THE MOST CONSEQUENTIAL AND SUCCESSFUL DEMOCRATIC PRESIDENT SINCE LBJ"

A lot of these facts are familiar to people who've been following Obamacare, but it's worth dwelling on them for a second. When you consider the law in the context of 100 years of progressive activism, and in the grand scheme of American history, it starts to look less like a moderate reform and more like an epochal achievement, on the order of FDR's passage of Social Security, or LBJ's Great Society programs. It is, to quote Harvard political scientist Theda Skocpol, "a century-defining accomplishment in the last industrial democracy to resist using national government to ensure access to health coverage for most citizens." FDR failed, Truman failed, Nixon failed, Carter failed, Clinton failed — and Obama succeeded. He filled in the one big remaining gap in the American welfare state when all his forerunners couldn't.

It's not just Obamacare

Obama shakes hands with Cuban President Raul Castro during the official memorial service for Nelson Mandela. (Chip Somodevilla/Getty Images)

And of course, the Affordable Care Act was hardly Obama's only accomplishment. He passed a stimulus bill that included major reforms to the nation's education system, big spending on clean energy, and significant expansions of anti-poverty programs. He shepherded through the Dodd-Frank Act, the first significant crackdown on Wall Street's power in a generation, which has been far more successful than commonly acknowledged.

He used executive action to enact bold regulations to curb greenhouse gas emissions, and to protect nearly 6 million undocumented immigrants from deportation. He ended the ban on gay and lesbian service in the military, made it easier for women and minorities to fight wage discrimination, cut out wasteful private sector involvement in student loans, and hiked the top income tax rate.

He reopened relations with Cuba after a failed half-century estrangement and has tentatively reached a historic deal to keep Iran from getting a nuclear weapon — and, much more importantly, to avoid a war with Iran. He reprofessionalized the Department of Justice and refashioned the National Labor Relations Board and the Wage and Hour Division of the Labor Department into highly effective forces for workers' rights.

His presidency holds massive symbolic value as proof that the reign of white men over American government can be halted and America as a whole can be represented. And while he was too slow in announcing support for same-sex marriage, he appointed two of the justices behind the Supreme Court's historic decision legalizing it nationwide, and enlisted his Justice Department on the side of the plaintiffs.

There are obviously places Obama fell short. I think he didn't take monetary policy nearly seriously enough, that the drone war is a moral catastrophe, that he's fallen short on combating HIV/AIDS and other public health scourges abroad, that the 2009 surge in Afghanistan was a mistake, and that perpetrators of torture and other war crimes from the Bush administration should have been criminally prosecuted. But while Obama could have accomplished more, it could never be said that he accomplished little.

"When you add the ACA to the reforms in the stimulus package, Dodd-Frank, and his various climate initiatives," Pierson says, "I don't think there is any doubt: On domestic issues Obama is the most consequential and successful Democratic president since LBJ. It isn't close." And LBJ's presidency was so marred by the Vietnam War that he declined to seek a second term — there is no similar stain on Obama's record.

You can generally divide American presidents into two camps: the mildly good or bad but ultimately forgettable (Clinton, Carter, Taft, Harrison), and the hugely consequential for good or ill (FDR, Lincoln, Nixon, Andrew Johnson). Whether you love or hate his record, there's no question Obama is firmly in the latter camp.