Suppose you did pay each legislator $50M to work for the good of the whole country. Do you think this would prevent Manchin from being influenced by a $5M lagniappe? It's an extra 10%! And a certain well-known politician infamously took care to fleece the secret service for overpriced golf cart and hotel room rentals, despite getting hundreds of millions per year in emoluments revenues. Some people are really motivated by every penny despite what economists might tell you about marginal utility.