Regarding Common Cause's call for SCOTUS Justices Scalia and Thomas to recuse themselves from campaign finance cases, Ed Brayton
responds:
Other justices speak at such political conferences frequently as well...Of course, the conservative justices tend to speak to conservative conferences and the liberal justices tend to speak to liberal conferences.
If the standard were that a justice had to recuse themselves whenever a case might involve someone who sponsors or is in a leadership position at one of those conferences -- conferences usually organized by very powerful people who are often involved in lawsuits -- then justices would have to recuse themselves in nearly every case of any significance.
If a liberal justice speaks to an American Constitution Society group or a conservative justice speaks to a Federalist Society function, it is almost certain that they will end up hearing a case that involves the law firms of those who organized and sponsored those gatherings. Those things tend to be organized by the top attorneys in the nation, the kind that do high-level appellate advocacy and are likely to appear before the court.
But Common Cause is going even further than that. They're arguing that a justice should recuse themselves from hearing a case that might negatively affect someone who organized or sponsored such a conference. That's even more broad and more likely to force recusal by more justices in more cases, to the point where you may, in many cases, have no justices at all that is not forced to recuse.
If that is the low standard for recusal, surely they would insist that a justice not hear a case that involves any organization that a justice used to work for. But Justice Ginsburg was once chief counsel for the ACLU. Should she have to recuse herself from any case the ACLU is involved in? Because they're involved in a hell of a lot of cases that make their way to the Supreme Court.