President Lyndon Johnson took office with vastly sweeping domestic programs in mind. His Great Society programs were aimed at reducing poverty, addressing systemic racism, reforming education, protecting the environment, and lowering crime. A number of these petered to an unsuccessful end. It is commonly thought that the Vietnam War was responsible for this.

To pay for both the war in Vietnam and these domestic programs, Johnson's advisors urged him to call for higher taxes. Johnson initially resisted this, as he knew it would be a political nightmare. Eventually, Johnson called for tax increases in 1967 to pay for both the war and Great Society programs. His political opponents said that they would only support the tax hikes if he made spending cuts. In the end, it became impossible to fund both the war and these domestic reforms. As a result, some of the domestic reforms that Johnson sought fell by the wayside.

Johnson felt that the Vietnam War had cost him so much in popularity that he could not run for reelection in 1968. The Democrats decided to run Hubert Humphrey, a moderate who still supported American involvement in Vietnam. Humphrey's major primary opponent was George McGovern, who ran on an anti-war platform. The divisions within the Democratic party were largely responsible for handing the election to Republican Richard Nixon. Nixon ran saying he had a plan to end the war in Vietnam, but he never gave any specifics. This led many to vote for him, allowing him to win by a narrow margin. Nixon's domestic policy dismantled a number of Johnson's reforms. Nixon's domestic programs were characterized by what was called New Federalism, which shifted federal responsibilities to the states. However, the Democratic congress was often able to override Nixon's vetoes and enact several liberal domestic programs.

The Vietnam War drained money from domestic programs, including Lyndon B. Johnson's War on Poverty. The war cost a great deal of money, and it also started to cause high rates of inflation. The United States spent $168 billion on the war. In addition, Johnson started borrowing to finance the war and to pay for the War on Poverty, part of his Great Society program. At the same time, Johnson did not raise taxes, resulting in inflation by the late 1960s. Though Johnson decided to pass a 10% income "surcharge" in 1969, it was too little to stop the increasing rate of inflation, which would soar into the double digits in the 1970s. In addition, the surcharge itself was a drag on economic growth. In return for agreeing to pass the surcharge, Congress demanded that President Johnson cut $6 billion in domestic spending, which hurt programs intended to help the poor. In the end, it was impossible for Johnson to fund "guns and butter" (meaning the Vietnam War and the War on Poverty) at the same time. 

The Vietnam War hurt the domestic programs of our country, many of which were launched by President Johnson. Many of these programs were a part of his Great Society program. As our involvement in the Vietnam War increased in the mid-1960s, the cost of running this war increased significantly. This took away money from domestic programs, which impacted them negatively.

Additionally, as our involvement in the Vietnam War increased, President Johnson had to devote more attention to the war effort. The war was not going well, and public opinion against the war was increasing. This meant President Johnson was able to spend less time dealing with and/or developing domestic programs.

A third impact was that President Johnson did not run in the presidential election in 1968, mainly due to his unpopularity as a result of the Vietnam War. When the Republican candidate, Richard Nixon, won the election, the President developed policies that reduced federal programs while giving more power to the state and local governments to decide which programs they wanted to continue to have. These policies, which were conservative in nature, had a negative impact on federal domestic programs.

The Vietnam War was very harmful to the domestic programs of the United States, many of which were programs that President Johnson had developed.

The involvement of the United States in the war in Vietnam had a very negative impact on the social programs that were proposed by President Lyndon B. Johnson.  The war harmed Johnson’s domestic agenda in at least three ways.

First, it took money away from those programs.  The war in Vietnam cost a tremendous amount of money.  So did the social programs of the “Great Society.”  Government funds, of course, are not completely unlimited.  Therefore, there was a tradeoff.  The money spent on the war had to end up reducing the amount of money that could be spent on Johnson’s programs.

Second, it took Johnson out of office.  President Johnson was eligible to run for reelection in 1968.  He might well have won.  However, the Tet Offensive and the war in general forced him into the decision not to run again.  With him out of the running, Richard Nixon won the election and a move in a more conservative direction began.  This harmed the domestic programs as well.

Finally, the war led to deep divisions in American society and these divisions did not help the Great Society programs.  America started to divide into liberal and conservative camps much more than it had in past decades.  The deepening conservatism, driven in part by anger at the counterculture and at civil rights and upheaval in the black community, led to much less support for Great Society programs.

In these three ways, the war in Vietnam made Johnson’s social programs much less viable.