Luther was part of Dorr's
Rebellion, and was attempting to overthrow the government of Rhode Island.
He was arrested for trespassing by Borden.
Luther challenged his conviction
by claiming that the Rhode Island government was unconstitutional because
it didn't grant voting rights to enough people and was therefore not
Article IV, Section 4 of the US Constitution (aka the Guarantee
Clause) tates that "the United States shall guarantee to
every State in this Union a Republican Form of Government."
Luther argued that since the
government of Rhode Island was unconstitutional, Borden was not acting
with proper authority when he made the arrest.
The US Supreme Court upheld
The US Supreme Court found
that it is Congress that determines which government is the legitimate
government of a State. If they treated Rhode Island's government as the
legitimate government, then it was.
The Court found that they
did not have the authority to rule on the legitimacy of a State
government. That was a political question outside the scope of judicial authority.