Harrison was an unsuccessful dark-horse aspirant for the Republican nomination in 1884. In 1888 he became a more formidable candidate when Indiana delegates endorsed his nomination and the most preeminent of Republican politicians, James G. Blaine, did not again become a candidate. With a field that at one juncture consisted of nineteen candidates, the organizers of Harrison's race, led by Louis T. Michener, attorney general of Indiana, concentrated on gaining the second-choice votes of the delegates until the final ballot.
Matt Quay, overlord of Pennsylvania Republicans, offered support in return for a blanket promise of a cabinet post. Harrison rebuffed his managers, who urged him to accept the deal, by recalling his instruction at their departure from Indianapolis that "purchasing capacity" must not supersede moral competency in deciding the nomination. A critical juncture in Harrison's progress was reached when Chauncey M. Depew, head of the New York delegation and president of the New York Central Railroad, with the approval of the state's real political boss, Thomas C. Platt, brought the New York delegation into the Harrison fold.
Harrison was nominated on the eighth ballot. The many ballots were telltales of his political weakness. He subsequently acknowledged to Blaine his indebtedness: "Only the help of your friends made success possible." Other factors favoring Harrison were his name, his war record, and his popularity with veterans. Levi P. Morton, a New York banker, was nominated for vice president. The Democrats re-nominated incumbent President Grover Cleveland, with Allen G. Thurman, a former Ohio senator, as his running mate.
Harrison conducted a "front-porch campaign" from his home. Imaginative pretexts were spawned to bring great crowds of visitors there. On "German Day," large delegations from Chicago and Milwaukee journeyed to Indianapolis, where they heard from Harrison a eulogy on German virtues. For one of the more imposing receptions, some forty thousand drummers converged from eleven states.
The principal issue in the campaign was the tariff, with Harrison calling for high tariffs and Cleveland, who did not campaign actively because he felt it beneath the dignity of the presidency, advocating lower tariffs. The contrasting positions on the tariff reflected basic differences between the Republican and Democratic parties in the decade 1884–1894, with Republicans espousing doctrines of nationalism and active governmental intervention to promote the expansion of the economy. The Democrats, under Cleveland, advocated states' rights and opposed the employment of national governmental power to speed economic growth. Harrison was severely pressured to make a strong commitment to service pensions for Civil War veterans. Sensing that the public might not welcome costly outlays, he limited himself to general pledges and platitudinous statements about veterans. A skilled formulator of positions on issues that served his political necessities, Harrison promised "liberal treatment" of veterans' pensions.
The Harrison campaign was lavishly financed, and its prime money-raiser was John Wanamaker, the Philadelphia department store magnate and chairman of the campaign's finance committee. Wanamaker was given "unrestricted power in raising and deciding upon the expenditure of funds." As a governing principle, he believed it "right" to solicit businessmen's contributions, and an imposing fund was raised "so quickly," Wanamaker noted, "that the Democrats never knew anything about it." In his expenditures, Wanamaker emphasized a "campaign of education" by salaried speakers and tons of protective tariff literature. His ebullient enterprise prompted charges that he was softening up the public to tolerate expensive favors from the future Harrison administration to business contributors.
As election day neared, Harrison was confident, predicting that "if we can secure an approximately fair election, I think we are safe." His attainment of a majority of the electoral votes—233 to Cleveland's 168—with only a minority of popular votes was aided by his successes in large states. His plurality in New York of 14,000 gained him 36 electoral voles, and he repeated that pattern of narrow popular-vote victories in such major electoral vote states as Indiana, Illinois, Michigan, Ohio, and Pennsylvania. So evenly was the vote distributed nationwide that the election became described as one of "no decision." Cleveland had a slight popular majority of about 100,000, largely because of increased Democratic majorities in southern one-party states.
Another major factor was the Republican campaign fund of over $400,000, the expenditure of which was concentrated in crucial states. Also of prime importance was Tammany Hall's betrayal of Cleveland, which helped Harrison carry New York. Despite Harrison's caution on veterans' pensions, the premier veterans' organization, the Grand Army of the Republic (GAR), was converted by his nomination and campaign into an instrument of the Republican party.