Constitutionally, yes, they can.
Practically, no. It was tried once and failed.
Constitutionally, [Supreme Court Justices can be impeached]. Practically, no. It was tried once and failed.I thought that might be the answer. It should be difficult to impeach a SCOTUS judge (otherwise it would be really political), and I suspect that Roberts is clever enough to walk the line and keep it hard to impeach him.