"The judicial Power shall extend to all Cases, in Law and Equity, arising under this Constitution, the Laws of the United States, and Treaties made, or which shall be made, under their Authority; to all Cases affecting Ambassadors, other public Ministers and Consuls; to all Cases of admiralty and maritime Jurisdiction; to Controversies to which the United States shall be a Party; to Controversies between two or more States; between a State and Citizens of another State [Modified by Amendment XI]; between Citizens of different States; between Citizens of the same State claiming Lands under Grants of different States, and between a State, or the Citizens thereof, and foreign States, Citizens or Subjects.
In all Cases affecting Ambassadors, other public Ministers and Consuls, and those in which a State shall be Party, the supreme Court shall have original Jurisdiction. In all the other Cases before mentioned, the supreme Court shall have appellate Jurisdiction, both as to Law and Fact, with such Exceptions, and under such Regulations as the Congress shall make."
This crisis has arisen not because the Justices of the Supreme Court are or are not impeached.
It has arisen because of the repeated failure of Congress to make proper exceptions to, and regulation of, the appellate jurisdiction of the Court, as they are charged to do by Art. III, s. 2.
A Congress so weak as to fail in its written duty to make exceptions to and regulate the appellate jurisdiction of the Court will NEVER IN A MILLION YEARS consider the much more radical, and much less well-documented, step of impeachment and removal of one or several justices.
Also the following excellent quote from Mr. Jefferson:
[T]o consider the judges as the ultimate arbiters of all constitutional questions [is] a very dangerous doctrine indeed, and one which would place us under the despotism of an oligarchy. . . . The Constitution has erected no such single tribunal.
He [Jefferson] further explained that if the Court was left unchecked:
The Constitution . . . [would be] a mere thing of wax in the hands of the judiciary which they may twist and shape into any form they please.