It's not about raw dollars, it's about political influence, which goes far beyond campaign contributions. "The money" refers to corporations that have influence above and beyond campaign dollars, but have continuing influence throughout the tenure of politicians, and afterwards through donations to other projects, "speaking fees", honoraria, post-political-career employment, investments (look at how many politicians have investments in companies that receive favourable legislation and tax breaks).
And then there is the media coverage during the election, which tends to be much more favourable to one candidate over another, depending on who the corporate ownership/board supports. And the backroom cronyism, since politicians have to come from somewhere, and typically it's money, some having served on the boards or upper managment of the corps and maintain their contacts. Not to mention their influence over an entire political machine, such as the DNC.
And, of course, politicians always look toward their next campaign, and have no interest in alienating their most important sources of ongoing funding and support by enacting unfavourable legislation. Look at the Disney-spearheaded changes to copyright law over the last half-dozen decades, for example.
Raw dollars spent on a campaign is not even close to the whole story.
Interestingly many corporations contribute to both sides of an election, hedging their bets.