Here’s a working thesis with potential: you have highlighted an important aspect of the novel for investigation. However, it’s still not clear what your analysis will reveal. Your reader is intrigued but is still thinking, “So what? What’s the point of this contrast? What does it signify?” Perhaps you are not sure yet, either. That’s fine—begin to work on comparing scenes from the book and see what you discover. Free write, make lists, jot down Huck’s actions and reactions. Eventually you will be able to clarify for yourself, and then for the reader, why this contrast matters. After examining the evidence and considering your own insights, you write:
The main argument of this imaginary thesis would be that a political system like ours incorporates corruption into its operations as a condition for its maintenance. In short, corruption is functional to the system. The system’s default is to reproduce itself. Nothing will compel it to change except persistent pressure from outside the system. If the other institutional systems—the mass media, the Church, the economic system, the law, etc.—can generate enough noise and irritation over its performance, the political system will have no choice but to pause, reflect and reform.