The Supreme Court is a literal oligarchy - it's 9 people who are accountable to no-one. The Senate is a more democratic body, since they can be held to account by voters.
I don't know if this was meant to be a joke but it's rather preposterous. Justices do not make laws, they interpret and apply them, and must do so while being rationally bound and yes accountable to laws and precedent under the framework of common law. Judicial activism is a pejorative term for good reason: they're not there to create or destroy laws. If they did start abusing their power to interpret laws they would be impeached: they actually ARE accountable to congress same as the president.
Also, if the equal protection clause was misinterpreted by the judicial branch, the legislative bodies of the federal and state governments have the power to revise and make it clear that the law was never to be interpreted that way.
