Final answer:
The political cartoon by Thomas Nast symbolizes the corrupting influence of money in politics by illustrating Boss Tweed with a moneybag for a head, indicating that his actions were driven by financial gain.
Step-by-step explanation:
The author of the political cartoon depicting Boss Tweed is making a statement regarding the corrupting power of money in politics and, by extension, Boss Tweed's role in that corruption. By replacing Tweed's head with a money bag, the cartoonist Thomas Nast emphasizes that Tweed was driven and led by monetary gain rather than any sense of civic duty or ethical leadership. This image suggests that Tweed's decision-making and influence were bought rather than earned through legitimate means, effectively symbolizing the broader issue of political corruption and monetary manipulation in government affairs.