13. Investor Timothy Mellon gave $10 million, mostly to Republicans.

Total donations: $10,061,000 ($10,058,300 to conservatives, $2,700 to liberals)

Party Affiliation: Republican

Net worth: $1 billion

Timothy Mellon, the grandson of twentieth-century business magnate Andrew Mellon, funded the founding of New Hampshire-based railroad company, Guilford Transportation Industries, according to Forbes.

While most of Mellon's donations were to conservatives, Mellon also gave $2,700 to Rep. Alexandria Ocasio-Cortez, according to The Guardian.