WASHINGTON — The Supreme Court is speaking with one voice in response to recent criticism of the justices’ ethical practices: No need to fix what isn’t broken.The justices’ response struck some critics and ethics experts as tone deaf at a time of heightened attention on the justices’ travel and private business transactions. That comes against the backdrop of a historic dip in public approval as measured by opinion polls.Deeply divided on some of the most contentious issues of the day &mdash …