I follow Biglaw for a living, and even I had forgotten that Sen. @JoeLieberman is at Kasowitz (as senior counsel, not a partner).
Former politicos at firms are commonplace (& less exciting than former exec-branch officials, who generate much more business).https://twitter.com/jdewey72/status/1037750536882323457 …
Depends; these arrangements are individually negotiated. But generally not tied to overall firm income.