That's the entire basis for the government. That only those who are willing to put the needs of humanity ahead of their personal needs are allowed to serve in the government..

It's not perfect but the idea is that the type of people to accept bribes to damage society would be weeded out before they would be eligible to run for office.

Remember when this book was written. This was right after WWII. A lot of people thought that we'd never do something like that again. A war to end all wars.