[wrycoder]

Well, look at 2018 compared to 2020 - they are similar.

State and the USPS are a little different - State looks outwards, unlike the rest of the agencies, and the USPS is quasi civil service and a bit of a political football. Not only that, but it has a strong local presence across the country.

The rest of the agencies are, unfortunately, politicized and biased.

Edit: Not all the charts in your link show cumulative data.

But, look at the chart for "Party Split, 1990-2022" in the election years - that's when the civil service donates heavily to get "their party" into power: 2012: Dem 69% 2016: Dem 77% 2020: Dem 76%

That chart includes both "Public Officials" and "Civil Servants". The former group is far more balanced, since the Republican/Democratic split is pretty even. If there was a similar chart for just the Civil Servants, it would be a lot more biased.