Democratic presidential candidate Hillary Clinton smiles as Sen. Bernie Sanders speaks in Portsmouth, N.H., where Sanders endorsed Clinton for president. (Andrew Harnik/Associated Press)

WHEN SEN. Bernie Sanders endorsed Hillary Clinton, he declared an ideological victory. His “revolution” lives on, he said, as he highlighted several issues on which Mr. Sanders has pulled Ms. Clinton left, and as he talked up the party’s platform — “by far the most progressive platform in the history of the Democratic Party.”

In fact, Ms. Clinton has managed to keep her basic message intact, and it is not Mr. Sanders’s overheated call for populist revolution. Her center-left philosophy has more emphasis on left now than it did eight or 16 years ago. But more important than incremental differences on the ideological spectrum is the question of how the country can and should be governed. On that crucial issue, Ms. Clinton is still attempting to appeal to a broad swath of the country looking not for angry upheaval but calm competence.

Certainly, Mr. Sanders and the populist tone of this election year have had an effect on the Democratic ticket. On the good side of the ledger: Ms. Clinton emphasizes important issues such as income inequality, campaign finance reform and climate change with more focus than a Clintonian Democrat from the 1990s would. Mr. Sanders also pressed for the party to support carbon pricing, the best policy to cut carbon dioxide emissions, in the platform. On the other hand, Ms. Clinton felt as though she had to flip against the Trans-Pacific Partnership — a strong deal that would cement U.S. influence in the Pacific Rim. Ms. Clinton also had to compromise her college affordability plan, which had been based heavily on channeling aid to the authentically needy, to write off tuition for a lot more students.

Yet Ms. Clinton refused to surrender on a range of issues, from banning fracking, which neither she nor the party endorsed, to creating a single-payer health-care system, a dream on which the party will not run. Throughout the campaign, Ms. Clinton has stuck to her guns on foreign policy, which is more hawkish than Mr. Sanders and a good number of Democrats would prefer. Although Ms. Clinton has adopted some Sandersesque hyperbole about how the economy is “rigged,” she did not promise to unnecessarily break up the banks.

In other words, Ms. Clinton and the Democrats successfully rejected Mr. Sanders’s core message: The country is an exploitative oligarchy so awful that nothing short of scrambling up the whole system will do. Instead, Ms. Clinton stuck with her approach of incremental, achievable change, and the party largely ratified it. She would modify the health-care system President Obama has labored to establish, rather than forcing the country through another, much more disruptive health-care transition. She would expand Social Security, but only for needy seniors, rather than wasting federal money handing wealthy people larger checks. By not banning fracking, she would allow cheap, domestically produced natural gas, which is much cleaner than coal, to continue serving as a bridge fuel to even-cleaner renewables.

Democrats have no doubt moved left over the past several years, but the party has been less volatile than the GOP. Ms. Clinton has maintained her message of working within the country’s political structures to tackle genuine issues the nation cannot ignore, and in ways that would be broadly acceptable to Americans. It is the message of a moderate liberal in the style of Mr. Obama, not the democratic socialist from Vermont.