While some of her new colleagues feared the former First Lady would be a dilettante who disdained legislating, she surprised them by plunging into the details of the job and gradually earned a reputation as one of the Senate's most substantive members.
She displayed the same style in her weeklong trip to the Middle East and Europe this week, and it was a sharp contrast to her approach on her maiden trip as secretary to Asia in February, where she made headlines with frank and sometimes jarring comments playing down the importance of human rights in the U.S.-China relationship and speculating about a possible succession struggle in North Korea.
Clinton on her second trip was substantive and unspectacular—dispatching envoys to Damascus, carefully navigating the Israeli-Palestinian peace process, announcing President Barack Obama's visit to Turkey and meeting with her counterpart from Moscow.
It was important but safe diplomacy, most of which will only pay off, if it ever does, over the next few months and years, much the way Clinton's early work in the Senate paid off for her there.
The trip also made clear that Clinton and her staff are still figuring out how she intends to carry out her new job-and how much the style she used in the Senate and more recently in her presidential campaign can be applied to diplomacy.
It's a process that every new secretary of state goes through, but the process is especially interesting for Clinton, whose fame and background make her an object of fascination to almost everyone she meets. Everywhere she went, Clinton recalled earlier visits as First Lady or as a senator.
Clinton's loss to Obama for the Democratic party nomination last year adds another element of uncertainty to the question of how she will operate. Hillary is a star, almost as much as Obama himself, and her celebrity gives her a tool she seems intent on exploiting, both within the administration and overseas.
At almost every stop on her trip Clinton conducted some sort of public meeting or town-hall gathering intended to either highlight a policy priority of hers or to spread the message that she and the Obama administration are making far-reaching changes in U.S. foreign policy compared to the Bush years.
In Brussels Clinton spent an hour fielding questions from young Europeans, who gave her two standing ovations.
Her predecessor as secretary, Condoleezza Rice, regularly held similar meetings early in her tenure, but was nowhere near as comfortable as Clinton at standing before an audience and explaining complex foreign policy ideas in terms that most people can understand. Eventually Rice's interest in such events dwindled to around one per trip.
But Clinton clearly loves the forums, which allow her to expound on issues like women's rights and the need for universal health care that go well beyond the usual portfolio of a secretary of state.
At times, Clinton's appetite for outreach can make her trips sometimes resemble a presidential campaign more than an official trip of the secretary of state. On Friday, during a stop in Ankara, she appeared on a popular Turkish afternoon talk show called "Come and Join Us," for an hour-long chat with the four women hosts. Rather than foreign policy, the discussion verged close several times into awkward and gossipy questions about Clinton's relationship with her husband Bill after the Monica Lewinsky affair.
"How did you cope during your life with those bitter times," one questioner asked. Clinton gave her standard answer: "Love, forgiveness and friendship," she said.
The setting for the television show was also a reminder of the clear advantages Clinton brings to her job. The show was taped in the same building where Bush White House adviser Karen Hughs had been screamed at by Turkish women several years earlier over the Bush administration's policies toward the Arab world. Clinton received nothing but goodwill and applause.
Still, Clinton's trip to the Middle East came at an unpromising time for attempting to restart the Israeli-Palestinian negotiating track. Israel is in the midst of choosing a new government and Hamas militants in Gaza continue to lob rockets across the border and tussle with Fatah, based on the West Bank for leadership of the Palestinian cause.
The unsettled environment left Clinton little room to maneuver and little prospect of real achievement coming out of her visit to Israel and the West Bank. Yet it would have been almost impossible to avoid an early trip to the Middle East, after she and Obama promised early and aggressive action on the peace process.
Public fascination with Clinton and the new administration inevitably will fade, which is probably why she is moving early to establish her position as a substantive player within the administration.
The Obama administration has set up a top-heavy foreign policy-making structure that seems to rely heavily on powerful envoys to do much of the day-to-day diplomacy. On her trip Clinton disputed suggestions she was uncomfortable with having so many envoys on foreign policy problems, describing herself as "100 percent committed" to extensive use of special envoys "because it gives you extra capacity for managing issues."
But her grueling schedule and pitch-perfect answers on sensitive issues during the trip may help put to rest the notion that she plans to function as a sort of diplomatic CEO, leaving the heavy work of the department to Richard Holbrooke, Obama's special representative for Afghanistan, or former Senator George Mitchell, who is the Middle East envoy.
It was Clinton during a stop in Brussels, who announced that the U.S. wanted to hold an international conference on Afghanistan and invite the Iranians to attend. An administration official said the idea of "big tent" meeting had originated with Holbrooke, partly as a way to test Iranian willingness to cooperate with the Obama administration in stabilizing Afghanistan.