President Lyndon B. Johnson and Dr. Martin Luther King Jr. stand out as remarkable co-architects of the movement for racial progress and just democracy that marked the decade of the 1960s. Individually, each put an indelible stamp of the civil rights and Great Society eras. Together, for a time, they formed perhaps the most formidable political tandem between a president and social justice movement leader in American history. Yet their relationship was also a fraught one,  filled with creative tension, political conflicts, and personal disappointments. This chapter delves into the arc of Lyndon Johnson and Martin Luther King Jr.’s relationship to tease out the extraordinary ways they were able to galvanize America toward some of the most remarkable achievements of the nation’s Second Reconstruction; yet, by the end of the public political careers, they grew increasingly distant, combative, and disappointed in the other. Ultimately, the chapter argues that, despite their political differences, their evolving relationship helped to fundamentally transform postwar American democracy even as it framed the limits of the political liberalism within which such change could occur.