Instead, in a hastily scheduled speech in a dreary hotel ballroom on Wednesday, Mrs. Clinton gave her concession speech, declaring the country “more deeply divided than we thought.”

“This loss hurts,” she said. “But please never stop believing that fighting for what’s right is worth it.”

The weaknesses in her candidacy, Ms. Dunn and other Democratic leaders said on Wednesday, were more than demographic. Though she and outside groups raised half a billion dollars to take on Mr. Trump with the most sophisticated ground game modern politics had seen, spanning the barrios of Orlando, Fla., black churches of North Carolina and the casinos of Nevada, the rationale for her run seemed more of a repudiation of Mr. Trump than Mrs. Clinton’s own positive vision for the country.

Even Mrs. Clinton’s closing chant in the final days of her campaign — “Love trumps hate!” — sounded like a play on her opponent’s name rather than her own inspiring vision.

Her campaign had built-in contradictions and challenges. She wanted to make history as the first female president, but she did not want to play it up so much so that she would turn off men. She vowed to help the little guy, but she accepted millions of dollars for speeches to Wall Street. She wanted to bring the country together, but she suffered from a stubbornly high number of voters who did not trust or like her.

Mrs. Clinton’s campaign tested out 84 slogans. There was “She’s Got Your Back,” “Strength You Can Count On” and “Real Fairness, Real Solutions.”

“Do we have any sense from her what she believes or wants her core message to be?” Joel Benenson, the campaign’s chief strategist and pollster, asked the chairman of her campaign, John D. Podesta, ahead of a New Hampshire speech, according to a hacked email that was among the thousands released by WikiLeaks.