If you threw a contested 8 million pounds into the US election in 2016, you might not crack the top 20.
Here are the individuals who have dipped deepest into their own pockets for campaign contributions to federal candidates, parties, political action committees, 527 organizations, and Carey committees. Only contributions to Democrats and Republicans or liberal and conservative outside groups are included in calculating the percentages the donor has given to either party.
To read more on Open Secrets:
https://www.opensecrets.org/overview/topindivs.php?cycle=2016&view=fc