In 2008, Hillary Clinton was running a campaign to restore the economic prosperity of the 1990s to America. She of course lost. In 2013 and 2014, her supporters launched an effort called "Madame President," trying to excite Democrats around the idea of Clinton as the first female president. But young women have voted in droves for Bernie Sanders.
Clinton started her second presidential run last spring promising to help "everyday Americans," a phrase she subsequently dropped. During her campaign, Clinton and her team have come up with two new slogans: the candidate says she wants to restore "love and kindness" to the country and finish "breaking down barriers." Neither has really stuck.
If Clinton eventually defeats Sanders as expected (even while losing some of the remaining contests against Sanders), polls suggest she will enter the general election far less popular than Obama was at this time in 2008 and as one of the most disliked major presidential candidates ever.
But Clinton may finally have a rationale that will excite voters about putting her in the White House: preventing a Trump presidency. Prominent figures from Massachusetts Sen. Elizabeth Warren to Republican Mark Salter, a former top adviser to John McCain, have pledged to strongly oppose Trump, while saying almost nothing about the former secretary of state who they will be sending to the White House if their efforts are successful. Current Secretary of State of John Kerry, who usually avoids speaking about domestic politics, told the graduating class at Northeastern University in Boston last week that "you are the most diverse class in Northeastern's history."
"In other words you are Donald Trump's worst nightmare," he added.
The specter of a Trump presidency could help Clinton bring Sanders' supporters and other Democrats wary of Clinton into her fold, although that was likely to happen anyway. (In 2008, polls suggest that the vast majority of Clinton supporters voted for Barack Obama, despite their claims in the midst of the heated primary that they would not.)
And the desire from elites in both parties to stop Trump may help Clinton build a deep and bipartisan coalition. In 2008, the prospect of electing the first-ever black president combined with the controversial nomination of Sarah Palin as vice president not only rallied reluctant Democrats behind Obama, but also pushed some Republicans, like Colin Powell, to publicly embrace the Democratic candidate.
Clinton's team, as Obama's did in 2008, is likely to organize some kind of "Republicans for Hillary" and target disaffected Republican voters and elites, particularly former GOP elected officials who don't have to worry about being challenged in a future Republican primary. (In an interview Sunday with CBS News, Clinton hinted at this approach, saying, "I have had a lot of outreach from Republicans in the last days.")
On her campaign website, Clinton is keeping a running list of Republicans who have said they will not vote for Trump.
"The biggest impact is to give some sense of mission to her candidacy," said Julian Zelizer, a political historian at Princeton University. "Meaning, she is not an inspirational candidate and generally people vote for her because they think she will be good at the job, not because she moves them. But with Trump as the opponent, this campaign will become literally a mission for many Democrats and Republicans to save the country from something that is really dangerous."
"It will create the kind of energy that has been missing from her campaign," added Zelizer.
An election against Trump may change the tactics of Clinton's campaign and potentially how she governs the country if elected.
Traditionally, in a general election, candidates spend a lot of time telling voters about their backgrounds, introducing their families to the electorate and emphasizing their non-political side in appearances on talk shows like "Ellen."
The 2004 Democratic National Convention, for example, was full of references to Kerry's military service.
Clinton has, to some extent, been campaigning nationally since 1992. She has been successful enough at wooing voters to help her husband get elected president twice, win two Senate elections in a state where she had not previously lived, get millions of votes in 2008 and be on the cusp of the Democratic nomination now.
But the numbers don't lie: Clinton has not convinced America to like her that much. A majority of Americans have an unfavorable view of Clinton, with some surveys showing Trump as one of the few politicians to surpass her unpopularity. Just 32 percent of Americans said they viewed Clinton favorably in a recent NBC News/Wall Street Journal poll.
In contrast, a Washington Post/ABC News poll in April 2008 found that 56 percent of Americans had a favorable view of Barack Obama, a number that surged to 63 percent that June. Only about a third of Americans had an unfavorable view of him.
Running against Sanders has accentuated some of Clinton's weaknesses, a policy vision some Democrats view as uninspiring and an inability to find a clear, compelling message.
Ari Ratner, who worked on Obama's 2008 campaign and then as an aide under Clinton at the State Department, said that Clinton has always had a clear rationale for her candidacy, "to push the progress that we made under President Obama." That argument has not been that compelling in a race against Sanders, but could be against Trump.
"It has been easy for someone--like Sanders-- to challenge her on the left with clearer, although often completely unrealistic proposals. But now she has a clear opposition with sharply contrasting values on foreign policy, on the economy, and on social policy," said Ratner.
Trump may help Clinton towards a campaign that illustrates her strengths and allows the former secretary of state to emphasize her experience instead of trying to be charming. His self-professed lack of interest in policy details is a favorable contrast to the wonky Clinton.
Trump's at times inflammatory comments toward women will make it easier for Clinton to run a campaign in which she discusses her gender directly, as she would like to do anyway.
"The leading Republican contender is the man who led the insidious birther movement to discredit the president's citizenship. And when he was asked in a national television interview to disavow David Duke and other white supremacists who are supporting his campaign, he played coy," Clinton told the Detroit NAACP in a recent speech.
"We cannot let Barack Obama's legacy fall into Donald Trump's hands," she added, essentially telling the majority-black audience that this campaign is about Obama and Trump as much as Clinton herself.
None of this guarantees Clinton will win. Stopping Trump was eventually the defining argument of the presidential candidacies of Jeb Bush, Ted Cruz and Marco Rubio, and a whole movement of activists in the GOP. They all failed, and Clinton could as well.