In a video released on April 25, Joe Biden declared that Americans “are in a battle for the soul of this nation.” He spoke about American values as iconic images of D-Day, Iwo Jima, and Dr. Martin Luther King flashed past. In a crowded Democratic primary full of candidates espousing their visions of America’s future, Joe Biden is running on its past.

“America’s an idea,” Biden continued, “an idea that’s stronger than any army, bigger than any ocean, more powerful than any dictator or tyrant. It gives hope to the most desperate people on earth, it guarantees that everyone is treated with dignity and gives hate no safe harbor.” But while he described his vision of what America is, he neglected to inform voters what he’d do with it during his four years in office.

Biden may not need to carefully outline his policies. He has more name recognition than any other candidate in the field due to his eight years serving as Obama’s vice president. Biden can vaguely hint that his policies are a continuation of the Obama years and thus tie his candidacy to a president who remains extremely popular on the left.

Running a campaign on American values has its perks. It is an easy way for Democratic candidates to position themselves as the antithesis to Donald Trump, a president whose conduct is widely detested on the left. While voters may desire more concrete policies, they find it hard to oppose a values-based candidate. 74% of Democrats have a favorable view of Joe Biden; just 15% oppose him.

Electability will be a major issue in the campaign as well. Democrats may eschew ideology in favor of supporting the candidate with the best chance against Donald Trump. In a recent Quinnipiac poll, thirty-five percent of respondents on the Left gave Biden the best chance to topple Trump in 2020; Bernie Sanders came a distant second, with seventeen percent. Biden is more moderate than many candidates in the Democratic field, and moderates tend to run better in presidential elections. His appeal to white working-class voters could overturn Trump’s advantage in the key electoral states in the Rust Belt, and he has a solid base of support among black voters due to his close connection to President Obama.

Yet for all his advantages, Joe Biden would be an awkward standard-bearer for the modern American left. While he remains firmly planted in the centre, the Democratic party is increasingly becoming more liberal. Candidates are announcing a host of policies to demonstrate their progressive bona fides. Bernie Sanders proudly calls himself a “democratic socialist.” Elizabeth Warren has announced a sweeping plan to forgive student debt and make public college education free, among a host of other left-wing policies. Cory Booker’s baby-bonds program would create a government-run savings account for each newborn in order to combat rising wealth inequality.

Biden may suggest that his lengthy political career speaks for itself, but to modern Democrats his career raises red flags. In the early 1970s he was a vocal opponent to new busing policies that accompanied the desegregation of schools. He pushed through comprehensive criminal legislation that opponents say helped bring about the era of mass incarceration in America.

It is on women’s issues that Biden seems most out of touch with his party. His conduct during the Anita Hill testimony in 1991 sits uncomfortably with many Democrats in the era of #MeToo and reminds many of the ugly spectacle of the Brett Kavanaugh hearings. In March a Nevada Assemblywoman named Lucy Flores accused Biden of inappropriate behavior during a 2014 rally, where Flores claims that Biden “inhaled [her] hair” and “planted a big, slow kiss on the back of [her] head.” Biden made light of the report a week later at a conference sponsored by the International Brotherhood of Electrical Workers, joking that he “had permission to hug” the union president Lonnie Stephenson.

Though Biden is the front-runner, he is not unassailable. Other Democratic candidates have similar advantages in electability. Numerous polls suggested that Bernie Sanders would have beaten Donald Trump in the 2016 election. Pete Buttegieg and Amy Klobuchar have demonstrated their electability in the Midwest. Kamala Harris and Cory Booker may be able to cut into Biden’s lead among black voters, especially in the key primary state of South Carolina.

Joe Biden hopes that his vision of American values will resonate with voters hoping for a return to normalcy. He is trying to recreate the New Deal coalition that dominated American politics for much of the twentieth century by offering Americans the safety of a shared past rather than the uncertainty of a turbulent future. Whether that coalition is still compatible with the Democratic voting base remains to be seen.