Repeal means wiping out a law already on the books. A legislative body has the power not only to pass new laws, but also to do away with laws that have been passed earlier. Sometimes, the legislature may pass an act which directly states that an earlier law is repealed. Such an act is known as an express repeal. Sometimes, a new law may simply make it quite clear that an older one no longer applies. In this case, the repeal is known as a repeal by implication. A new law will sometimes conflict only with a certain portion of an earlier one. The new law is understood to repeal by implication those parts of the earlier law that are inconsistent with it.
To avoid confusion, legislatures often enact an express repeal of a law which has already been repealed by implication. For example, the passage by Congress of the Kansas-Nebraska Bill had the effect of repealing the Missouri Compromise. But Congress later passed a second bill specifically declaring the Missouri Compromise “void and inoperative.”
