The term “liberal Republican” has in many ways become an oxymoron in modern American politics. Even moderate Republicans find themselves on the defensive, derided by pundits like Rush Limbaugh and the GOP's dominant, vocal right wing as “RINOs” (Republicans in name only) for being insufficiently dogmatic in support of cherished conservative policies. One need look no further than the 2010 midterm elections or the contest for the 2012 Republican presidential nomination to witness the reality of this phenomenon. This was not always the case, however. For the first two decades after World War II, Republicans waged an intense internecine conflict between liberals and conservatives over the GOP's identity as the party tried to reclaim the White House from the Democratic Party.

In The Roots of Modern Conservatism, Michael Bowen analyzes this struggle and its ramifications. Bowen argues that the roots of modern conservatism run much deeper than many scholars, who focus on the grassroots movement that began to coalesce around Senator Barry Goldwater of Arizona in the late 1950s or the influence of William F. Buckley and National Review, recognize. Instead, he contends that attention should be focussed on the struggle for dominance between the factions headed by the two leading figures in the Republican Party in the 1940s and early 1950s – Governor Thomas Dewey of New York and Senator Robert Taft of Ohio – which “turned into a deeper questioning of philosophical principles and polarized the party between self-identified liberals and conservatives” (3). These tensions, he suggests, helped determine the future direction of the party. According to Bowen, Dewey and Taft went from being “rivals who espoused a number of similar policies in 1944 to bitter enemies warring across an insurmountable chasm eight years later” (5).

As governor of New York, Dewey embraced the notion of a more inclusive Republican Party that would provide New Deal benefits with greater efficiency, thus allowing the GOP to appeal to the working class and minority groups and provide a successful challenge to the Democratic incumbent in the White House. As a result, he garnered the support of those Republicans who considered him the more electable candidate. Taft appeared as the champion of conservative ideals and received the support of the party's “Old Guard.” Indeed, “Mr. Republican” believed that the previous two decades had been a political aberration and that a platform that supported free-market economics, low taxes, and small government would bring the increasingly conservative American electorate back to the Republican Party.

The book examines these intramural debates from an insider's perspective, focussing particular attention on how both Dewey and Taft tried to convince the GOP elites that their respective approaches would allow the party to win a general election. In many respects, these internal divisions were less about policy positions and more about rhetoric, positioning, and how the two factions used ideology “as a way to discredit their rivals” (74, 129). Bowen examines important political moments like the 1948 election campaign, the creation of the FEPC, and the role of organized labor, and concludes that Dewey and his forces were able to outmaneuver both Taft and the new generation of conservatives because of their political acumen, not necessarily because their ideas were more popular (203). Yet he also demonstrates that while Dewey's faction won more battles – perhaps most significantly the nomination of Dwight Eisenhower in 1952 – Taft and his followers actually prevailed in the long term. The book's concluding chapter describes how Eisenhower's moderate policies angered and alienated conservatives and “provoked them to challenge the administration and the GOP from within” (173). As a result, Bowen contends, the political paradigm shifted. When Eisenhower left office in 1961, the new right emerged as the most potent force within the party and was determined to relegate the moderation of Dewey and Eisenhower to the past.

Bowen does a nice job in detailing the strife between Dewey and Taft and their respective factions. The book falls short of the breadth that one might expect based on the title, however. Bowen spends very little time discussing the various and occasionally discordant strains that comprise modern conservatism: economic conservatives, libertarianism, and the grassroots conservative activism of groups like the Young Americans for Freedom are virtually absent from the narrative Bowen presents, as is a sense of analytical nuance in dealing with the very real political and ideological differences between Taft and his conservative successors in the GOP from Goldwater to Reagan. Nevertheless, the book represents a useful expansion of the narrative regarding the evolution of the Republican Party specifically and postwar American political development generally.