Hillary Clinton began her campaign for the Democratic nomination as firm favourite, but started facing difficulties as soon as the primary contests began.
Here are some memorable quotations from the ups and downs of her campaign.
20 January 2007
"I'm in, and I'm in to win."
A message on her website, declaring her intention to run. It continued:
"So let's talk. Let's chat, let's start a dialogue about your ideas and mine, because the conversation in Washington has been just a little one-sided lately, don't you think?"
24 July 2007
"I thought that was irresponsible and frankly naive."
Her first attack on a rival candidate - a comment on Barack Obama's statement in a televised debate that he would be prepared to meet the leaders of Iran, Syria, Cuba, North Korea and Venezuela in his first year in office.
16 September 2007
"When I'm president, we're going to get it done — we're going to have universal healthcare."
A comment at Senator Tom Harkin's annual Steak Fry in Indianola, Iowa. At this stage in her campaign, when she was widely regarded as the inevitable Democratic candidate, she used the phrase repeatedly. Journalists noted seven repetitions in one day.
26 November 2007
"I think everybody should just take a deep breath and say, 'Let's just go to the finish line,' which will probably be midnight West Coast time on 5 Feb," Hillary Clinton told CBS News anchor Katie Couric.
"If it's not you, how disappointed will you be?", Couric asked.
"Well, it will be me."
5 January 2008
"Well, that hurts my feelings... but I'll try to go on."
Hillary Clinton responded with a smile to a question, during a televised debate, why New Hampshire voters didn't like her as much as Obama, according to opinion polls. She added:
"He is very likeable, I agree with that… I don't think I'm that bad."
In the same debate she attempted to undermine Mr Obama's claim to be the candidate of change:
"I want to make change, but I've already made change. I will continue to make change. I'm not just running on a promise of change, I'm running on 35 years of change… so you know, I think it is clear what we need is somebody who can deliver change. And we don't need to be raising the false hopes of our country about what can and can't be delivered."
7 January 2008
"It's not easy, it's not easy, and I couldn't do it if I just didn't passionately believe it was the right thing to do."
Hillary Clinton became emotional and teary eyed on eve of the New Hampshire primary. She went on:
"I have so many opportunities for this country. I don't want to see us all fall back.
"This is very personal for me. It's not just political, it's not just public — I see what's happening. We have to reverse it.
"Some people think elections are a game — it's about who's up and who's down," she said. "It's about our country's future, it's about our kids' future — it's really about all of us together."
8 January 2008
"I come here tonight with a very, very full heart, and I want especially to thank New Hampshire. Over the last week, I listened to you and in the process I found my own voice. I felt like we all spoke from our hearts and I am so gratified that you responded.
"Let's give America the kind of comeback that New Hampshire has just given me."
From her victory speech, after winning the New Hampshire primary.
21 February 2008
"Lifting whole passages from someone else's speeches is not change you can believe in, it's change you can Xerox."
Mrs Clinton accused Mr Obama of plagiarism at a debate in Texas. The audience booed.
In the same debate, she held out an olive branch:
"You know, no matter what happens in this contest - and I am honoured, I am honoured to be here with Barack Obama - I am absolutely honoured. Whatever happens, we're going to be fine. You know, we have strong support from our families and our friends."
3 March 2008
"I think I know what's happening, and I believe we are going to do well tomorrow, and I believe that's going to be a very significant message to the country. And then we move on to Pennsylvania and the states beyond.
"So, I'm just getting warmed up."
Speech to a rally in Toledo, Ohio, a day before her victories in the Ohio and Texas primaries.
24 March 2008
"I remember landing under sniper fire. There was supposed to be some kind of greeting ceremony at the airport, but instead we just ran with our heads down to get into the vehicles to get to our base."
Mrs Clinton's account of landing in Bosnia during the war, part of a speech delivered in Washington.
25 March 2008
"You know I have written about this and described it in many different settings and I did mis-speak the other day. This has been a very long campaign. Occasionally, I am a human being like everybody else."
Mrs Clinton withdraws her earlier account of braving snipers in Bosnia, in comments to a Pittsburgh radio station.
The same day, she went on the attack in an interview with the Pittsburgh Tribune-Review editorial board, criticising Barack Obama for his links to his controversial former pastor, Jeremiah Wright:
"You don't choose your family, but you choose what church you want to attend.''
1 April 2008
"Let me tell you something, when it comes to finishing a fight, Rocky and I have a lot in common. I never quit. I never give up. And neither do the American people."
Mrs Clinton was speaking in Philadelphia, in the long run-up to the Pennsylvania primary, which, when it came, temporarily revived her campaign.
In her preamble to this remark, she said:
"Just as it's getting time to vote here in Pennsylvania, Senator Obama says he's getting tired of it. His supporters say they want it to end.
"I know what it's like to stumble. I know what it means to get knocked down. But I've never stayed down, and I never will."
21 April 2008
"I want the Iranians to know that if I'm the president, we will attack Iran… In the next 10 years, during which they might foolishly consider launching an attack on Israel, we would be able to totally obliterate them."
Mrs Clinton answered a question from anchor Chris Cuomo on ABC News' Good Morning America, about what she would do as president if Iran attacked Israel with nuclear weapons.
23 April 2008
"I think I am better prepared and able to take on Senator McCain - apparently Democrats in Pennsylvania agree with that."
Mrs Clinton speaking hours after her victory in the Pennsylvania primary.
8 May 2008
"There was just an AP article posted that found how Senator Obama's support among hardworking Americans, white Americans, is weakening again, and how whites in both states who didn't complete college were supporting me. I have a much broader base to build a winning coalition on."
Mrs Clinton speaks more bluntly than ever about the race question in the Democratic nomination race, after narrowly winning the Indiana primary, and losing heavily in North Carolina.
13 May 2008
"I am more determined than ever to carry on this campaign until everyone has had a chance to make their voices heard."
Mrs Clinton celebrates her win in West Virginia, at a time when most analysts say she has no chance of winning the nomination.
She also says:
"I will work my heart out for the nominee of the Democratic Party to make sure we have a Democratic president."
23 May 2008
"My husband did not wrap up the nomination in 1992 until he won the California primary somewhere in the middle of June, right? We all remember Bobby Kennedy was assassinated in June in California. I don't understand it."
Clinton tells the editorial board of the Sioux Falls Argus Leader newspaper she does not understand the calls for her to quit. Critics said her reference to Bobby Kennedy was distasteful, taking into account the popular fears of a possible attempt to assassinate Barack Obama.
Later she apologised:
"I regret that if my referencing that moment of trauma for our entire nation and in particular the Kennedy family was in any way offensive. I certainly had no intention of that whatsoever."