It's rare that such large sums would go through the campaign-finance slot. Supposedly Biden received only $200k from the credit card industry for his awful bankruptcy "reforms". Of course larger bribes are paid, but they are less direct and less public. One method I've seen up close (I worked for Lucent back when they were in business) is to hire close relatives of favored politicians at vastly inflated salaries for "show-up" jobs for which those relatives had no observable skills. Those relatives would eventually transfer large portions of the millions they "earned" to the politician, but there was no hurry. In addition, there are sweetheart "investment" opportunities that somehow are only offered to politicians. We've all heard about the exorbitant "speaking fees". ISTR a mayor somewhere published a book and arranged for certain constituents to buy thousands of copies of it. Avaricious politicians have imagination.
Perhaps you're thinking of "Healthy Holly," a series of self-published children's books for which Mayor Pugh was paid over $800000, which came to light last year.
