"Elohim you shall not curse" — the Torah prohibits cursing judges. But the Mekhilta asks: why is this verse necessary? From (Exodus 22:27), "and a prince in your people you shall not revile," we already learn that cursing leaders is forbidden. And "prince" could encompass judges as well as political leaders.
The answer is that each prohibition generates independent liability. If a person curses a judge, he violates "elohim you shall not curse." If he curses a prince, he violates "a prince you shall not revile." These are two separate commandments, not one.
The practical consequence is significant. If a person curses someone who is both a judge and a prince — holding both judicial and political authority — he violates two prohibitions simultaneously. Each prohibition attaches its own penalty. The person is liable "for each in itself."
This is characteristic of the Mekhilta's approach to overlapping commandments. When the Torah states two prohibitions that cover similar ground, the rabbis do not treat one as redundant. Each prohibition has its own scope and its own legal force. Overlap does not create redundancy — it creates compounded liability. The more offices a person holds, the more prohibitions protect him from verbal abuse. This layered protection reflects the Torah's view that communal leaders deserve heightened dignity, and violations of that dignity deserve heightened consequences.