The reason for this exponential leap in political spending, if you talk to most Democrats or read most news reports, comes down to two words: Citizens United. The term is shorthand for a Supreme Court decision that gave corporations much of the same right to political speech as individuals have, thus removing virtually any restriction on corporate money in politics. The oft-repeated narrative of 2012 goes like this: Citizens United unleashed a torrent of money from businesses and the multimillionaires who run them, and as a result we are now seeing the corporate takeover of American politics.

As a matter of political strategy, this is a useful story to tell, appealing to liberals and independent voters who aren’t necessarily enthusiastic about the administration but who are concerned about societal inequality, which is why President Obama has made it a rallying cry almost from the moment the Citizens United ruling was made. But if you’re trying to understand what’s really going on with politics and money, the accepted narrative around Citizens United is, at best, overly simplistic. And in some respects, it’s just plain wrong. …

…Legally speaking, zillionaires were no less able to write fat checks four years ago than they are today. And while it is true that corporations can now give money for specific purposes that were prohibited before, it seems they aren’t, or at least not at a level that accounts for anything like the sudden influx of money into the system. According to a brief filed by Mitch McConnell, the Senate minority leader, and Floyd Abrams, the First Amendment lawyer, in a Montana case on which the Supreme Court ruled last month, not a single Fortune 100 company contributed to a candidate’s super PAC during this year’s Republican primaries. Of the $96 million or more raised by these super PACs, only about 13 percent came from privately held corporations, and less than 1 percent came from publicly traded corporations.