In the 1824 presidential election, Van Buren backed the Republican caucus nominee, Treasury Secretary William H. Crawford. The two had a great deal in common: Crawford was a states' rights advocate, a strict constructionist, and—a consideration of overriding importance to Van Buren—a dedicated party man. But the Republican coalition was rapidly splintering, and many Republicans, calling for reform of the nominating process, refused to heed the will of the caucus. Four other candidates ultimately entered the race, all claiming membership in the party of Jefferson: Secretary of State John Quincy Adams, Secretary of War John C. Calhoun, Henry Clay, and Tennessee senator Andrew Jackson. Consumed by his single-minded effort to secure Crawford's election, even after his candidate became so seriously ill that he could neither see, hear, nor walk, Van Buren was bitterly disappointed when the House of Representatives elected Adams president.
After the election, Van Buren, as the new acknowledged leader of the "Crawford" Republicans, also known as "Radicals," kept his peace while others denounced the "corrupt bargain" with Henry Clay that many suspected had elevated Adams to the White House. He voted to confirm Clay as secretary of state, but he broke his silence after Adams outlined an ambitious domestic and foreign policy agenda in his first annual address. Van Buren particularly objected to the president's plan to send representatives to a conference of South and Central American delegates in Panama and enlisted the aid of Vice President John C. Calhoun and his allies in an effort to prevent the confirmation of delegates to the conference. The Senate ultimately confirmed the nominees, but the debate over the Panama mission had helped forge a tentative coalition of "Radicals" and Calhoun supporters under Van Buren's leadership.
In December 1826, the Little Magician formalized his alliance with Calhoun, who had already pledged his support for Andrew Jackson in the forthcoming presidential race. Each man had his own agenda: Calhoun intended to succeed Jackson, after serving a second term as vice president; Van Buren, alarmed by Adams's grandiose agenda and convinced that Republicans had strayed from the Jeffersonian creed, intended to restore the party to its "first principles." Jackson, he was convinced, should carry the reinvigorated party's standard in 1828. "If Gen. Jackson…will put his election on old party grounds, preserve the old systems, avoid if not condemn the practices of the last campaign," he predicted, "we can by adding his personal popularity to the yet remaining force of old party feeling, not only succeed in electing him but our success when achieved will be worth something."
By December 1827, Van Buren had assumed control of the Jackson campaign. The candidate remained in the background while the Little Magician orchestrated a battle plan of unprecedented energy and vigor. His campaigning was, in the words of one scholar, "little short of brilliant." Van Buren plunged wholeheartedly into the contest, serving as fund raiser, strategist, publicist, and counselor. Several states had, prior to the election, revised their election laws to expand the franchise. With parades, rallies, speeches, and calls for "reform," Van Buren and his lieutenants mesmerized these first-time voters, as well as others who had become disenchanted with the administration. "The American people," a Jackson scholar concluded, "loved the performance put on for them."
Keeping his fragile coalition together represented Van Buren's most difficult challenge, apart from persuading the candidate to suffer in dignified silence as the Adams camp levelled increasingly virulent attacks on his character. The growing protectionist sentiment in the West and in the Northeast posed particular problems for Van Buren, who could not afford to alienate southern free-trade advocates. Courting both camps, he studiously avoided making a definitive pronouncement on the tariff, even as he deftly guided a protectionist bill through the Senate. The 1828 tariff, known in the South as the "Tariff of Abominations," reassured westerners, who might otherwise have remained in the "Adams-Clay" fold, that a Jackson administration would take their interests into account. Van Buren realized that protectionism was anathema to southern agriculturalists, but he also realized that most southerners regarded Jackson as the lesser of two evils. As one scholar has conceded, during the tariff debate Van Buren "said some very equivocal things to Southerners," helping them convince themselves that, once elected, Old Hickory would support tariff reform.