What a difference four years makes if you’re Hillary Clinton.

In March 2008, though she would remain a presidential candidate for several more months and win some big primaries, she was defeated and discredited. Barack Obama was sweeping most contests and House Speaker Nancy Pelosi said it was unacceptable for then-Senator Clinton to try to use controversial rules to wrest the nomination.

Obama’s campaign outperformed hers, starting with the Clinton miscalculation that her support for the Iraq War would be an asset. Her husband, former President Bill Clinton, was tarred for his overzealous support for her.

After the election, when the president-elect surprisingly offered her the post of secretary of state and she surprisingly accepted, there were more than a few predictions of disaster. She now is completing what she has said will be the final year of a successful stint as the top U.S. diplomat.

A testament to her standing is the opening she has to become president of the World Bank. Others, including former Treasury Secretary Larry Summers, are panting for the job. It would be Clinton’s for the asking. No one matches her global profile and political skills.

She’s not asking for it and wouldn’t take it.

Exhausting Run

In part, friends say, that’s because she’s exhausted after a grueling year and a half running for president, followed by a punishing schedule as secretary of state. Unstated is that on Nov. 7, the day after the presidential election, she will be the front-runner for the 2016 Democratic nomination, regardless of who wins the presidency this time or whether she plans to run.

In contrast to four years ago, she’s the most popular American, far outshining Obama. She’s celebrated as a diplomat and rock star around the globe.

“She has made people all over the world more respect, appreciate and understand America,” says one of her predecessors, Madeleine Albright. “She has made very clear what American values are while at the same time understanding other countries’ national interests.”

There are detractors. On Afghanistan, she was on the prevailing side in arguing to send more troops in 2010. As that war continues to look like a quagmire, even some former supporters of the war now wish Vice President Joseph Biden’s more skeptical stance had won the day.

She’s played a less than major role in many of the administration’s big decisions on defense and intelligence: the killing of Osama bin Laden, the use of drones and relations with Pakistan, and even some of the debates about Iran.

Moreover, great secretaries of state have close relationships with presidents: George C. Marshall and Harry Truman, Henry Kissinger and Richard Nixon. The Clinton-Obama relations are professional, cordial, not close. The “Team of Rivals” line that this president’s advisers trumpet -- Obama is like Abraham Lincoln in embracing former political opponents as intimate advisers -- is more appearance than reality.

The White House national security advisers, whose primary objective often seems to be protecting this president’s political interests, have been a source of tension with the secretary. This isn’t unusual. The only time, it is said, when the secretary of state and NSC adviser enjoyed complete mutual respect and regard was in 1973-75; that’s when Kissinger held both jobs. (Actually the other time was in President George H.W. Bush’s administration, when Brent Scowcroft had the job, creating a model that every successor has unsuccessfully sought to emulate.)

Morale Raiser

Still, she gets credit for lifting morale at the State Department and making good appointments. Colleagues say she still misses the friendship and counsel of the late Richard Holbrooke, who compensated for Clinton’s lawyerly bent by being an idea machine and geostrategic thinker in the Kissinger and Zbigniew Brzezinski mold.

She was a key figure in decisions leading to the toppling of Libyan dictator Muammar Qaddafi, and is deeply involved in Asian affairs, including the relationship with China.

The secretary has brilliantly projected America’s soft power -- or “smart power,” as she prefers to say --emphasizing the role of women, public/private partnerships, the use of technology and social media and global health issues.

With a few exceptions, such as Pakistan, U.S. relations with most countries are better than they were four years ago. Her personal diplomacy is omnipresent. There seemingly is no place she won’t go to meet women’s groups, plant a mangrove tree, kiss a baby or impress a politician.

She has spent 299 days on the road, traveling 731,680 miles, visiting 95 countries.

She bears little resemblance to candidate Clinton of 2008, who often was stiff and distant; she had an especially cold, distrustful relation with the press. Secretary Clinton is more natural, even down-to-earth, excelling at personal relations with world leaders. She is relatively open with reporters showing a sometimes warm and funny side that wasn’t on display four years ago.

When she steps down at the end of this presidential term, friends says she wants a respite before any new undertaking. She’s likely to park for a while at the William J. Clinton Foundation. Well-informed Clintonites are divided over whether she’ll seek the presidency again; most say, surprisingly, that she has thought little about it and it’s an open question.

If she decides to run, she will need to assemble a much better political operation than she had last time, when she stubbornly stuck with her choices when even longtime loyalists pleaded with her to change.

Another issue might be age; she’d be 69 right before Election Day 2016. If she ran it would be a test of the persistence of sexism, of whether age matters more for women than for men. She would be younger than Ronald Reagan when first elected or Bob Dole and John McCain when they were nominees or Republican hopefuls Newt Gingrich and Ron Paul will be on Election Day this year.

As this surprise-filled political season has demonstrated, it’s hazardous to predict the climate four weeks from now, much less four years. And, polls notwithstanding, a Hillary Clinton political comeback would be an unlikely saga.

Then again the Clintons have made comebacks and unlikely sagas their stock in trade.

(Albert R. Hunt is the executive editor for Washington at Bloomberg News. The opinions expressed are his own.)

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To contact the writer of this column: Albert Hunt in Washington at ahunt1@bloomberg.net

To contact the editor responsible for this column: Max Berley at mberley@bloomberg.net.