The judicial branch does not have unlimited powers.
Practically so.
The highest officials in government are always above the rule of law, and this is especially true for Judicial branch which determines the constitutionality of laws and the constitution itself.
The empty words of the constitution that Justice Clarence referred to can be spinned to support partisan political positions. The decision on the unconstitutionality of same sex marriage in 2015 was an example of the Supreme court stretching to fulfill a political agenda, or did you not hear the majority opinion on that case?
The justices are affiliated by party, have the ability to choose cases, and can exercise court orders. The Supreme Court is essentially a government all by itself.