When Barack Obama took office in January of 2009, there was no end to the problems that needed fixing. Some 30 million Americans did not have health insurance. Hundreds of thousands of people had lost their jobs the previous year, and millions more would join them in subsequent months. The financial industry was broken but, like some ticking time bomb on pause, still posed a serious threat to the global economy. Two of the nation's largest automakers were heading toward bankruptcy. And the country was drained and chastened by its greatest foreign policy disaster since Vietnam.

The catastrophe of the Bush presidency was so deep and wide that it sometimes seemed that Obama would never claw out of its shadow. He also frequently hurt his own cause, in particular by clinging to his image as a bridge-building uniter even when it was clear that the minority party was actively using his bipartisan overtures to slow and defeat his agenda.

But as we enter the twilight of the Obama era, he can boast numerous achievements: an economy slowly but surely approaching full employment; a landmark health care law that has produced clear results for millions of people; a financial regulatory regime that, while watered down, is starting to shrink Wall Street; and a patchwork of environmental regulations and bilateral climate change agreements that could finally put the U.S., and possibly the world, in a position to address global warming.

In contrast, Hillary Clinton, who officially announced her campaign for president on Sunday, will not face the same array of challenges should she be elected — which is another way of saying that she will have fewer opportunities to remake the political landscape in her image. Her candidacy is not a campaign for change, but a call for going onwards and upwards. Though her team would be loath to admit it, she is essentially running for Barack Obama's third term.

But there is still plenty for Clinton and the Democratic Party to do — and plenty of space to leave her mark.

First, simply by virtue of being elected, Clinton could consolidate the gains that Democrats have made in the Obama era. Her liberal detractors like to say that she is virtually indistinguishable from likely Republican opponent Jeb Bush, but that misses the fact that a President Bush would be under enormous pressure to roll back Obama's hard-won reforms in the areas of health care, financial regulation, and the environment. At the very least, Clinton would face pressure from her party and her base to protect those reforms. Her veto power alone could entrench progressive priorities for a minimum of four years, which would be crucial in making them intractable elements of the American polity. That alone would make her a good president.

Second, there is much more to be done. While pundits are fond of saying that the Democratic agenda has been exhausted, Obama has only left a foundation for reform. Health care coverage is far from universal, and still expensive. It is worth remembering that in 2008, Clinton actually ran to Obama's left on the issue, which should give progressives hope that policies like the public option and greater subsidies will be on Clinton's 2016 agenda.

Then there are the issues of wage stagnation and income inequality, two longstanding trends that will likely be at the heart of Clinton's pitch to voters. A recent report drafted by Clinton allies, including Neera Tanden and former Treasury Secretary Lawrence Summers, laid out what David Leonhardt at The New York Times described as the "first draft" of a Clinton economic platform: a mix of improving education, providing direct aid to the lower and middle classes, bolstering child care, strengthening financial regulation, raising taxes on the wealthy, and cutting taxes on the middle class.

Then there are three issues — gay marriage, women's rights, and immigration reform — that are of immense ideological and electoral importance to the Democratic Party, and can expect an ardent champion in Clinton.

The fear is that a President Clinton, likely facing a Republican-controlled Congress, will not be content to be the safeguard of Obama's legacy; that she will foolishly trade away Democratic priorities like entitlements in some ill-conceived Grand Bargain; that she will succumb to the many demons whispering in her ear, whether they be Wall Street bankers, neoliberal triangulators, purveyors of hoary Beltway wisdom, or the Wormtongue-like advisers that are always hovering around Clintonland. But if Clinton is smart, and I believe she is, she will realize that the days of repealing Glass-Steagall are over, and that her ticket to a historical legacy is to be part of a great era of policy reorientation away from the conservative-neoliberal consensus that has produced decades of middle-class stagnation and one huge financial crisis. Her public comments, at least, suggest she understands how the terrain has shifted.

To that end, there are ways Clinton could be a far more effective president than Obama. She never fell for the idea that Obama could unite the two parties through a mixture of sheer magnetism and Spock-like reasoning, famously mocking his supporters for believing that "celestial choirs will be singing" as soon as he stepped into the Oval Office. She knows the enemy, and is under no obligation, as Obama was, to make nice with the other side. She is also better at greasing her own side with the kind of glad-handing and thank-you-card-writing that Obama constitutionally dislikes — my guess is that another President Clinton would have an easier time getting her side to fall in line on, say, the Iran deal than President Obama. Combined with a presumably humbled GOP (a big presumption, granted), one can see how she could pull the levers of power more effectively. Barring that, she could use the power of her office to begin a campaign to put Congress back in Democratic hands in 2018 or 2020.

Foreign policy is a trickier question. It depends on whether you see Obama's foreign policy, which is so entwined with Clinton's tenure at the State Department, as a disaster for which the U.S. is primarily responsible or the result of organic crises erupting in the Middle East and elsewhere that are largely beyond the administration's control. Many critics have accused Clinton of helping turn Libya into a failed state, and note that her support for U.S. intervention echoed her support for the Iraq War. But at the risk of delving into hypotheticals, it's just as likely that Libya would have devolved into civil war anyway. True, she also supported sending arms to Syria's rebels, a position that seems all the more questionable with the rise of ISIS. But on important issues — from opposing new settlement building in the Occupied Territories, to supporting the nuclear framework with Iran — Clinton has not taken the hawkish side, as so many of her liberal critics fear she would do if she becomes president. At any rate, she is far better than almost any alternative offered by the Republican Party, which has fully relapsed into neoconservative belligerence.

None of this is to suggest that Clinton will be Robin to Obama's Batman. It is to say that the Democratic Party's hope of producing a Ronald Reagan-like figure — one who facilitates a sea change in how voters conceive of free markets, the role of government, and the uses of American power — may have to be supplanted by the idea of a tag-team job featuring the two titans of their party.