In addition to Excess of Democracy, Derek Muller has a post examining political contributions of employees (attorneys and employees) at the top 140 law firms in the United States. Interestingly enough, it turns out that donations to the vast majority of these companies are definitely leaning towards the Democratic Party.
From his post:
All in all, I raised about $ 61 million in contributions to Democratic-affiliated groups compared to about $ 11 million for Republican-affiliated groups in 2017-2020, almost a 6 to 1 ratio. . .
Many companies had less than 10% of the grants going to major Republican outlets. A handful had at least 25% and only three exceeded 50%. Even among those the figures are misleading. At White & Case, for example, there was a single $ 500,000 contribution to the Trump Victory Fund, more than half of all Republican contributions over this four-year period.