Senator Elizabeth Warren of Massachusetts plans to drop out of the presidential race on Thursday and will inform her staff of her plans later this morning, according to a person close to her, ending a run defined by an avalanche of policy plans that aimed to pull the Democratic Party to the left and appealed to enough voters to make her briefly a front-runner last fall, but that proved unable to translate excitement from elite progressives into backing from the party’s more working-class and diverse base.

Though her support had eroded by Super Tuesday, in her final weeks as a candidate she effectively drove the centrist billionaire, former New York Mayor Michael R. Bloomberg, out of the race with debate performances that flashed her evident skills and political potential.

She entered the race railing against the corrosive power of big money, and one long-term consequence of her campaign is that Ms. Warren demonstrated that someone other than Senator Bernie Sanders, and his intensely loyal small-dollar donors, could fund a credible presidential campaign without holding fund-raisers.