In the eyes of Croly, Henry Clay epitomizes a figure whose noble intentions were thwarted by a lack of execution. As a statesman, Clay advocated for a fusion of democracy and nationalism—an ideal Croly endorses. Nonetheless, he criticizes Clay and the Whig Party for their ineffectiveness due to poor organization. Clay's political career included serving in the House of Representatives from 1810 to 1814 and again from 1815 to 1821. Despite losing the presidential election of 1824 to John Quincy Adams, he became Secretary of State. Clay returned to the Senate in 1831, leading a vigorous opposition against President Andrew Jackson, whom he viewed as authoritarian, leading to the formation of the Whig Party. Yet, their efforts to shift public opinion failed. Clay's 1844 presidential campaign was also unsuccessful, marking a significant defeat for himself and his party. Undeterred, Clay rejoined the Senate in 1849. Croly criticizes Clay and the Whigs for failing to firmly uphold their beliefs, as articulated in his analysis of The Whig Failure:

"They believed that the consolidation and the development of the national organization was contributory rather than antagonistic to the purpose of the American political system, yet they made no conquests on behalf of their convictions."

Amidst the tales of European history, Croly delves into the significant impact made by German Chancellor Otto von Bismarck. He portrays him as a paragon of leadership—a man who adeptly harmonized his personal convictions with the needs of his nation. Ascending to the role of Germany's first chancellor in 1871, upon the declaration of William I of Prussia as the German Emperor, Bismarck wielded near-absolute authority over both foreign and domestic policies. Opposed to socialist ideologies in Germany, he sought to undermine their influence through an ambitious agenda of social reforms. Under his guidance, laws were enacted to provide insurance for sickness, accidents, and old age, alongside regulations to curb child labor and set maximum working hours. Croly applauds his resolute leadership, remarking on the formation of German national identity:

"Thus the modern German nation has been at bottom the work of admirable leadership on the part of officially responsible leaders; and among those leaders the man who planned most effectively and accomplished the greatest results was Otto von Bismarck."

In a dedicated portion of The Promise of American Life, Croly examines the reforms championed by Secretary of State William Jennings Bryan, though he remains distinctly unimpressed. Labeling Bryan's initiatives as "ill-conceived," Croly criticizes his muddled political vision, accusing him of advocating for increased federal authority while simultaneously expressing skepticism towards centralized governance. Bryan's political journey spanned terms as a Nebraska congressman from 1891 to 1895 and three unsuccessful presidential bids, before his appointment as Secretary of State by President Woodrow Wilson. His reforms included the introduction of income tax, direct election of senators, women's suffrage, and prohibition. Bryan also endorsed public railway ownership and the unrestricted minting of silver. However, Croly censures Bryan for his preference for moderation, noting:

"He stands for the sacrifice of the individual to the popular average; and the perpetuation of such a sacrifice would mean ultimate democratic degeneration."

Alexander Hamilton, the illustrious statesman and Secretary of the Treasury under George Washington, crafted a political philosophy that resonated deeply with Croly in The Promise of American Life . Despite acknowledging that Hamilton's advocacy for a potent, active central government was less favored than Thomas Jefferson's laissez-faire approach, Croly champions Hamilton's call for stringent federal regulation. One of Hamilton's perceived shortcomings, according to Croly, was his insufficient trust in the American populace. Nevertheless, Croly lauds Hamilton for his visionary belief that "Unionism must be converted into a positive policy which labor[s] to strengthen...

Andrew Jackson, the seventh leader of the United States, fervently opposed any form of special economic or political privilege, passionately asserting that "one man was as good as another." Croly critiques this belief, arguing it misguidedly stifled the development of exceptional talents among the American populace. However, he acknowledges Jackson's commanding and tenacious nature, which resonated with the masses, embodying the indomitable pioneer spirit. Croly contends that Jackson's most significant shortcoming was his failure to discern the divide between genuine patriotism and self-centered individualism. This oversight led to the fragmentation of various self-interests and factions, splintering the nation and contributing to the economic and political imbalance that Croly finds deeply troubling.

Abraham Lincoln, the sixteenth president of the United States, occupies a prominent position in The Promise of American Life. Croly dedicates an entire section to Lincoln’s policy decisions and outstanding statesmanship. He highlights Lincoln’s acute awareness of the contradiction between striving for a robust democracy with equal rights for all while permitting slavery to exist. Croly lauds Lincoln as the quintessential American politician and reformer, noting his ability to prioritize the nation’s needs over his own. Throughout the book, Croly extols Lincoln as the ultimate visionary, a man of compassion and exemplary statesmanship: "The life of no other American has revealed with anything like the same completeness the peculiar moral promise of genuine democracy."

William Travers Jerome, a lawyer and district attorney in New York from 1901 to 1909, earned a reputation for his forthright speech and reformist zeal, advocating for an end to "administrative lying." Although Croly acknowledges Jerome's strong moral fiber, he criticizes the narrowness of his platform, centered solely on honesty and integrity. Croly argues that Jerome's inability to enact real change stemmed from his lack of a compelling public persona and insufficient attention to pressing issues. As Croly observes:

Mr. Jerome’s weakness consisted in the fact that he had never really tried to lead public opinion in relation to state and national political problems, and that he was obliged to claim support on the score of personal moral superiority to his opponent.

In his extensive analysis, Croly critiques the policies of Thomas Jefferson, who ascended to the presidency as the third leader of the United States in 1801. Croly suggests Jefferson was mistaken in his conviction that the federal government should primarily focus on foreign matters, leaving local governance to states and municipalities. He criticizes this laissez-faire philosophy, claiming it permitted the country to drift into a state of economic and political disarray. Croly holds Jefferson accountable for his emphasis on individualism and calls for a departure from the "Jeffersonian principle of noninterference."

Theodore Roosevelt, presiding as president when Croly unveiled The Promise of American Life, receives praise within the book as a reformer brimming with potential. Croly commends Roosevelt for integrating nationalization into the reform movement and advocating for a "national idea." Croly coins the term "New Nationalism" to describe Roosevelt’s reform ethos, a phrase eventually embraced by the president himself. Croly asserts that Roosevelt liberated American democracy from its "Jeffersonian bondage" by providing individuals of "special ability, training and eminence" greater opportunities to serve the public. Additionally, Croly admires Roosevelt's unwavering faith in human nature.

William Randolph Hearst, who rose to prominence as the leader of a vast publishing empire and served as a congressman from 1903 to 1907, is harshly critiqued by Croly as the epitome of misguided reformers. Croly brands Hearst a "fanatic" and "demagogue," accusing him of fervently advocating for equal rights while condemning those responsible for past inequalities. Croly contends that Hearst's penchant for pandering to popular sentiment, alongside his radical views and incendiary rhetoric, undermined the nation's objectives. He denounces Hearst's ideology as "a living menace to the orderly process of reform and to American national integrity."

John D. Rockefeller, the American industrial titan, orchestrated the creation of the Standard Oil Company of Ohio in 1870, amassing a fortune through shrewd and ruthless business tactics. Croly uses Rockefeller as the epitome of the corrupt "business specialists" thriving due to the federal government's laissez-faire stance. He warns that men like Rockefeller will exploit every available avenue to further their personal interests unless stringent regulations curb their ambitions.

Stephen Douglas, a prominent figure in the House of Representatives from 1843 to 1847 and later a U.S. senator until his death in 1861, is best remembered for his participation in the historic Lincoln-Douglas debates of 1858. Croly discusses Douglas's stance on the contentious issue of slavery, highlighting his support for "popular sovereignty," a doctrine suggesting that the nation could accommodate the spread of slavery while safeguarding democratic principles.

American statesman and congressman Daniel Webster, labeled by Croly as a misguided reformer, is examined alongside Henry Clay and the Whig Party. Croly notes a significant blunder by the Whigs was their failure to confront the issue of slavery flourishing within a democracy. While acknowledging some positive national ideas espoused by Webster and his party, Croly points out their inability to implement reform, hindered by a lack of strong national sentiment.