In his State of the Union address on Jan. 10, 1967, Johnson proposed a 6 percent surcharge on individual and corporate taxes to pay for the war and expanding social programs. But the proposal stirred only acrimonious debate about the nation’s priorities. Wilbur Mills of Arkansas, the chairman of the House Ways and Means Committee and a staunch critic of Johnson’s domestic programs, immediately demanded deep cuts in domestic spending before any tax proposal would be considered.

From the left, too, came unwelcome attention to the connections between war and domestic reform. Above all, the Rev. Dr. Martin Luther King Jr., who had been quiet about the war, used a high-profile speech on April 4 to berate American leaders for a conflict that, like a “demonic, destructive suction tube,” pulled “men and skills and money” away from urgent tasks at home.

Things got only worse for Johnson. In August, revised estimates of American expenses in Vietnam and likely budget deficits led him to increase his surcharge proposal to 10 percent. He also accepted for the first time that he would have to give ground on spending: After months of dickering with an increasingly hostile Congress, on June 28, 1968, he signed legislation imposing the 10 percent surcharge but also requiring $6 billion in cuts to domestic programs.

In the end, Johnson had the “last laugh,” as his aide Joseph Califano Jr. put it. He had called Congress’s bluff: Unwilling to make difficult choices about cuts to domestic programs, legislators could find only $4 billion to slash from the 1969 budget, below the $6 billion Johnson had called for. In fact, that fiscal year ended with a $3.2 billion surplus and no significant unraveling of the Great Society. Johnson’s Great Society survived for decades and remains largely intact in the 21st century, thanks to the unwillingness of most conservatives to risk political fallout from tearing down programs that proved beneficial to millions of Americans.

Still, 1967 marked a turning point for Johnson and the transformative agenda that he championed — indeed, for postwar liberalism itself. Attacked by both left and right, Johnson could never again muster anything close to the congressional support he had once enjoyed. His achievements during the final year of his presidency consisted mostly of environmental and consumer-protection measures that carried small price tags, and crime-fighting bills that enjoyed conservative support. The 1968 Fair Housing Act, the final civil rights accomplishment of the 1960s, was possible only because the assassination of King momentarily changed the mood in Congress.

More bad economic news in 1968 not only reinforced Johnson’s frustrations domestically but also forced an abrupt change of policy in Vietnam. Confronted with mounting evidence that the war was contributing to a damaging drain on American gold reserves, Johnson saw no choice but to reject the military’s appeal for more troops and to seek ways to wind down the war. In a speech on March 31, 1968, he called for negotiations and stunned the world by announcing that he would not run for re-election.

The latter decision may have resulted primarily from Johnson’s concerns about his health, but it flowed as well from his failure, perhaps inevitable, to paper over the tensions between his foreign and domestic goals. He could not, as he put it after leaving the White House, have both “the woman I really loved — the Great Society” — and “that bitch of a war on the other side of the world.”