https://politics.stackexchange.com/questions/8383/u-s-presid...
No, not entirely, but it absolutely can and does factor into one's decisions in life, including who to contribute to politically.
> I'd imagine the vast majority of people see their employer as the means to pay bills rather than a political entity whose goals they explicitly support.
The vast majority aren't the ones typically contributing to political candidates/PACS. Contributions tend to be from those with wealth, which are inherently not the majority. In this particular case, that wealth is at least in part derived from the employers these employees work for. It's also not coincidence that those higher up in a company, and thus more invested in the company doing well, are the ones getting paid more.