The cartoonist used "$" instead of "s" for Senate as a play on words and visual pun. The "$" symbol is commonly associated with money and represents the U.S. currency. The cartoonist likely used this symbol to convey a message about the influence of money in politics or to satirize the idea that politicians prioritize financial matters over their actual role and responsibilities. The use of visual symbols in cartoons allows artists to convey complex ideas in a simple and humorous way, engaging viewers while making a point.
It was possible that he was trying to prove a point to the reader.
