That chart represents the relative number of employees, including lawyers, in the largest U.S. firms to contribute to Republicans. I have written several posts about the “ideological capture” of major U.S. professions and institution, and opined that the extreme progressive bias in the legal profession is among the most threatening to U.S. society and democracy itself. Two examples are here and here.
Right now the D.C. Bar is fighting with the Justice Department over the Trump administration requiring some major law firms to demonstrate that they are not biased against the President and his policies, an effort the Axis (and the D.C. Bar’s staff) calls making them “bend a knee.” The major law firms are biased against this President and his administration, and are increasingly willing to show it. The civil justice system will not work if the legal profession is politicized. Increasingly, it is.
The reason is pretty clear: the vast majority of law schools have almost no conservatives or Republican on their faculties, and my alma mater, Georgetown University Law Center, is typical of the top tier law schools. You can peruse GULC’s disturbing EA dossier here.
Ethics Alarms 
A college classmate environmental law partner at Troutman Sanders and a law school classmate and fellow articles editor at law school, now a partner at King and Spalding, both smart guys, are thoroughly Trump Deranged. Strangest thing I’ve ever seen. I attribute it to the fact they view Trump as a very serious, almost existential threat to the status quo upon which their entire worlds rest. Trump is simply a fox in the henhouse. Not “one of us.” Of course, my peers are retired or semi-retired now.
The issue is not so much theeir bias would inhibit their ability to represent clients who are suing, or being sued, by the Trump Administration, but whether they could fairly represent clients who sue or are being sued by a state administration opposed to the Trump administration, or a future administration with much different political priorities.