In March 1867 Congress enacted the first Reconstruction Act, with which the eleven former Confederate states had to comply in order to regain Congressional representation. Among the law’s stipulations was a requirement for black manhood suffrage. All but three states conformed, even though the demand for black manhood suffrage was very unpopular among white Southerners. (In 1870 the 15th Amendment would constitutionally oblige Northern states and the three unreconstructed Southern states to provide black manhood suffrage as well.)
This Thomas Nast cartoon alludes to the familiar biblical story of Samson as a way of emphasizing that voting rights (Samson's hair) is the source of societal strength for black men, which Southern Democrats (as Delilah) and their Northern allies seek to keep from them. Like other liberal Republicans, Nast considered political equality as both the foundation and safeguard of economic and cultural advancement.
The armed and dangerous Democratic figures in the left-background are (l-r): Wade Hampton holding a torch aloft; Nathan Bedford Forrest, wearing a Fort Pillow medallion; a squatting Robert E. Lee; presidential nominee Horatio Seymour, with demonically horned hair, wearing a Ku Klux Klan breastplate, and carrying a flag that commemorates slavery, the Confederacy ("lost cause"), the Ku Klux Klan, the Civil War draft riots in New York City, and he Reconstruction race riots in Memphis and New Orleans; vice presidential nominee Frank Blair, also wearing a Ku Klux Klan breastplate; Raphael Semmes; John Hoffman; and a stereotypical Irish-American Catholic in the shadow under Hoffman's arm.
In front of the Democratic politicos, a fire burns symbols of religion (the Bible) and knowledge (books, a scroll, and a globe). The writing on the center wall announcing “The Democratic Barbecue” refers to a typical 19-century political event by which candidates tried to rally public support (here, hypocritically of black men); it also echoes the catch-phrase “the great barbecue,” which signified political corruption. To the right is a statue of President Andrew Johnson as the “Moses” of black Americans, a promise undermined by his veto of Reconstruction legislation. Fittingly, he holds a tablet marked “veto” instead of the Ten Commandments. In the lower-right corner, a satanic copperhead snake (with horns like Seymour) laughs at Samson and his shorn hair.