In a series of well known decisions, Republicans on the Supreme Court have made it easy for big money to influence the outcome of election campaigns. The cynical side of me suggests that it is not a coincidence that these decisions are likely to help Republicans over the long haul.
So I find it surprising that in this difficult year for Democrats, the Democratic Party committees and the Democratic Super PACS are outraising the comparable Republican groups by substantial margins. See (Wall Street Journal subscription required). This does not include money given to 501 (c) (4) groups where disclosure is not required, but it is still worrisome to Republicans, like those at the Journal.
It ought to prompt some concern by the rank and file Democrats though because it is a vivid reminder that the Democrats depend upon large donations just as much as the hated Republicans. When Barack Obama first ran for President, much was made of the large amount of money he raised in small donations. Footnote: he raised immensely more in large donations.
Why are Democrats raising more? My best guess is that more businesses are recognizing that the scorched earth policies of the Republican Party are bad for business. Indeed, a large part of the money given to Republicans was designed to assure that Tea Party candidates not succeed in primaries. More important, who is backing the different parties? I am not sure that the top money givers lists are all that revealing. Of course, unions give to Democrats. Oil companies give to Republicans. The way some businesses hedge their bets is interesting. Some of the top Democratic contributors are liberals who earned their money in hedge funds. Are they merely public spirited (no doubt they are to a large extent), or do they also have business interests in the outcome? One thing for sure: we need more solid reporting on what candidates are promising in order to raise money.
For the top organizational money givers, see Open Secrets Organizations. For the top individuals, see Individuals. For some information on the top individuals giving money to the Democrats, see Steyer, Simons, https://www.nationaljournal.com/magazine/meet-fred-eychaner-the-most-mysterious-figure-in-democratic-party-politics-20140508, and https://en.wikipedia.org/wiki/Michael_Bloomberg.