If the Obama administration began with an idealistic sense of unbridled possibilities bordering on naiveté, a Hillary Clinton administration could open with a world-wearied recognition of limitations bordering on pessimism.

Clinton would be the first Democratic president since Grover Cleveland in 1893 to come into office without controlling both chambers of Congress, since Democrats can at most hope to win the Senate this year. And she could enter office distrusted and disliked by many if not most Americans, according to polls, and trailed by a whiff of scandal she has been unable to shake.

Republicans have already promised years of investigations and obstruction, and they want an especially early start to the 2020 campaign, convinced that a Clinton win would be more a sign of Donald Trump's weakness than anything.

Meanwhile, an emboldened left, regretting the running room it gave Barack Obama early in his first term, would not allow Clinton much of a honeymoon. And the specter of a primary challenge to Clinton's re-election may even be raised.

Given the circumstances, it's easy to wonder whether Clinton would have some buyer's remorse after pouring so much time, blood and sweat into winning the presidency.

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But even a weak president is the most powerful person on the planet, and Clinton seems prepared to grind out what she can. While not every president can be transformational, Clinton would be simply by being the first woman to occupy the Oval Office in 240 years of American history.

"I've long given up on magical unicorns that get everyone to get together and sing Kumbaya," said Jared Bernstein, who served as an economic adviser in the early years of the Obama White House, when it tried in vain to work with Republicans on major bipartisan deals. "But there's still a ton of important stuff that a President Clinton could do."

Like George H.W. Bush after Ronald Reagan, Clinton would inherit the legacy of a charismatic president who set the country on a new course. And her first and most important task would be to defend and entrench many of Obama's accomplishments.

In the language of football, while Obama looked for long passes, Clinton would probably have to slog through short running plays and defend yardage already gained.

"Will she suddenly discover a knack for inspiring people? I don't think so. She will be asked to be judged on the results of patience and hard work," said William Galston, a former Clinton White House official who is chairman of the Governance Studies Program at the Brookings Institute. "She's less charismatic than her husband but much better organized."

While Trump aimed for disruption, Clinton might only harden the status quo.

But if partisan trench warfare is inevitable, few people have more experience in the muck than Clinton.

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"There's nothing that she's going to confront that she hasn't faced before from Congress," said Rep. Xavier Becerra of California, chairman of the House Democratic Caucus. "So that should put her in a pretty good place to handle recalcitrant Republicans."

With the avenue for action largely obstructed in Congress, Clinton has already signaled that she's prepared to cut Congress loose and redirect energies to the executive branch and the judiciary, where should would have the opportunity to change the balance of the Supreme Court.

It took years for Obama to come to the conclusion that he needed to work around the GOP, while Clinton could skip that learning curve. So she's set goals in line with what she could control, like making the government look more like America, with a Cabinet that is half-female.

But she would need a Democratic Senate to confirm her nominees for both.

Progress where possible

Clinton's legislative agenda has been kept in line with that reality.

While her website lists dozens of policies "from Alzheimer's to Zika," as top policy adviser Jake Sullivan likes to say, she's promised to target only three major policy goals in her first 100 days.

In order of feasibility, they are: push for a jobs and infrastructure bill, introduce a comprehensive immigration reform and push for a constitutional amendment to overturn the Citizens United campaign finance court ruling, which is largely symbolic.

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The infrastructure package, likely paid for with some modest tax reform, is at the top of Clinton's priority list because it is widely seen in both parties as one of the few issues on which Republicans might be willing to work with a President Clinton.

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"In the approach that she takes to Republicans and in the issues that she prioritizes, she's not going to do anything to fritter away an opportunity to find consensus," said Brian Fallon, a spokesman for Clinton. "She intends to make the infrastructure jobs package the test of people's willingness to get something done."

Progressives are already pushing for the package to go beyond bridges and roads and the hard-hat jobs (read: male) they create, to include more human infrastructure like health and child care jobs (read: female).

"Our traditional notions of infrastructure are very gendered," said Heather McGhee, president of Demos, a liberal think tank.

Mary Kay Henry, president of the Service Employee International Union, said: "Service and care workers all over this country expect the next president to announce the most ambitious jobs program since World War II."

Competing priorities

There's a limited window for action in any new administration and especially one in which there would be little, if any, congressional willingness and bandwidth for legislating. So Clinton would have to triage competing interests of key interest groups in the Democratic coalition.

First and foremost would be Latinos, who feel frustrated by a lack of action on immigration in Congress and empowered to make demands by a surge in their turnout this year.

"We need to make sure that the fact that our community will be seen as essential in turning this election is considered and the issues that we care about will be given a heightened sense of priority," said Janet Murguia, president of the National Council of La Raza.

Given the divisive nature of the immigration debate, Murguia and others are hoping to reframe the issue around immigration's economic benefits, so it could coupled with or sequenced behind an infrastructure plan as part of major economic push.

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"There needs to be real serious run at legislation — an assertive, affirmative effort to address this in Congress," Murguia added. "We just need to make sure it is not seen as a side issue or a special-interest issue but as an issue that is integral to strengthening the U.S economy."

Bipartisan cooperation on immigration reform seems doubtful after the Republican Party nominated Trump, but Democrats are hoping a Trump loss would lead the GOP on another soul-searching process that allows moderates in the party to reassert themselves, especially on this issue.

"Trump has damaged the Republican brand with Hispanic voters to the point perhaps where it's beyond repair unless there is fast action among Republicans to be seen as reasonable and constructive on issues important to that community," Fallon said.

And if that's unsuccessful, a failed immigration bill could be converted into a messaging tool against the party. Meanwhile, Clinton has already threatened to use new executive actions to shield more people from deportations than Obama already if legislation fails, although experts say Obama may have already pushed executive authority to the limit.

Meanwhile, Clinton has promised Black Lives Matters activists to work on criminal justice and police. That issue had been building bipartisan enthusiasm in Congress, but it's unclear where it stands after Trump's embrace of a "law and order" message.

And she's told progressives and young voters that she would work to make dramatically reduce student debt and make college more affordable, an issue that is broadly popular with Americans.

At the same time, the Affordable Care Act would likely need some fixes that Republicans may be loathe to cooperate on.

Executive action

While she would likely try Congress first, there is no doubt that Clinton has embraced creative uses of the federal bureaucracy and presidential prerogative to enact her agenda.

Obama was reluctant, at first, to bypass Congress, but a key architect of his turn toward executive action in the second term was former White House counselor John Podesta, who is Clinton's campaign chairman.

Beyond immigration, Clinton has floated executive actions to expand background checks for buying firearms from other than licensed dealers and closing a tax loophole that benefits hedge fund managers, along with a host of other economic issues, like new rules on overtime pay that are already in the pipeline.

A challenge is that Obama has already picked the low-hanging fruit in many areas. But some, like climate change and energy, remain ripe.

"There's still an enormous amount of executive actions that can be taken," said Michael Brune, executive director of the Sierra Club.

From expanding or renewing expiring tax credits for clean energy to enacting stricter rules on natural gas and expanding pollution controls to all coal power plans, Brune hopes for "a compilation of what the Obama administration started." Advocates would also push for limits on natural gas extraction on public lands.

Foreign policy

Clinton would have to balance her domestic agenda with immediate challenges abroad, both to smooth things over with allies and calibrate a new posture towards Russia after an election that strained relations with both.

"Quite frankly, the campaign itself has changed the equation dramatically," said Wendy Sherman, former undersecretary of state for political affairs under Clinton, who is thought a likely candidate for secretary of state in a Clinton administration.

"First and foremost, because of our election campaign, Secretary Clinton as president will have to affirm our alliances and partnerships."

And as U.S. intelligence agencies prepare countermeasures to alleged Russian meddling in this year's election, according to NBC News, Moscow is moving back to the top of Washington's radar.

"I don't think anyone wants to return to the Cold War," Sherman said. "We will certainly work with Russia where we can, but we will challenge and confront Russia where we must."

Supreme Court

One of the first major decisions Clinton might have to make would be whether to re-nominate Merrick Garland for the Supreme Court, unless Republicans decide to give up their nine-month-long filibuster and confirm Obama's nominee during the lame-duck session of Congress after the election.

"It's a pivotal moment, given the current makeup of the Supreme Court," said Nan Aron, president of the Alliance for Justice, a progressive group that works on judicial appointments. "I think we can safely assume that no matter who she does nominate, and what the makeup of the Senate is, it will be an epic battle."

With just eight justices on the court, the stakes are tremendous. A Democratic-appointed justice who replaces the late Antonin Scalia would tip the ideological balance of the court from majority conservative to majority liberal.

For that reason, Republicans like Sen. John McCain have already suggested that they would block any Clinton appointee. So if Obama can get Garland confirmed during the lame-duck session, it would remove an enormous item from Clinton's to-do list next year. Confirming justices can consume months of Senate business and crowd out other priorities.

Liberals would prefer a younger and more progressive pick than Garland. But Clinton would likely have the opportunity to appoint two or even three more justices, not to mention fill the more than 100 open seats on lower court. Together, filling those courts alone could be a Clinton legacy item.

Go nuclear?

Republican obstruction on the Supreme Court would create an almost immediate crisis on the other end of Pennsylvania Avenue, where a potential Democratic majority would have to decide whether to eliminate the filibuster for high court picks starting from Day One of a new Senate.

Democrats already used a version of the so-called nuclear option to kill the filibuster for lower-court judges and executive branch nominees, but they preserved it for Supreme Court picks, meaning nominees would need a 60-vote supermajority to be confirmed.

It's procedurally easier for the Senate to change its rules on its opening days, and Sen. Chuck Schumer of New York, the incoming Democratic leader, from may face pressure from liberal members of his caucus to act.

"If we end up with a blockade and Hillary Clinton is not allowed to fill a Supreme Court position, it's really a constitutional crisis," said Sen. Jeff Merkley, D-Ore., the only senator to endorse Bernie Sanders and an advocate for rules reform in the upper chamber.

"I think we'd try to do everything we could before a rule change would be considered, but at the end of the day, you can't let a minority in the Senate destroy the Senate's constitutional responsibility," he said.