Answer:
Welfare reform
Step-by-step explanation:
In his campaign, Jimmy Carter had frequently asserted, ""If I'm elected president, you're going to have welfare reform next year." He promised to replace the problems of the existing system with one that would encourage work and family life, and that would "reflect both the competence and compassion of the American people." In August, 1977, President Jimmy Carter announced his proposals for reforming the welfare system in the United States.
However, President Carter's plan did not win support in Congress, and in fact never received a vote in Congress.
So welfare reform most definitely was a key issue for the Carter administration and addressed by his administration, but his reform plans were not enacted into law.
Note: The same thing could also be said about tax reform. The Carter administration proposed tax reform legislation which also was rejected by Congress.