The court was not investigating if their power had been suspended, they were ruling if they had the power to issue the writ in the first place. As the Chief Justice framed it, "The inquiry therefore on this motion will be, whether by any statute, compatible with the constitution of the United States, the power to award a writ of habeas corpus, in such a case as that of Erick Bollman and Samuel Swartwout, has been given to this court." The Chief justice pointed out the the judicial act laid out which courts could issue the writ of habeas corpus. The question then became was the Supreme Court included in that list? The Chief Justice ruled that it was. The final question was the act of Congress that gave the court the power to issue the writ compatible with the Constitution. And in this, too, Chief Justice Marshall ruled that it was. So none of these three questions addressed the issue of who may suspend habeas corpus because habeas corpus had not been suspended.
Who had the suspension authority and how did you legally determine, for the court, that it had not been suspended?
If habeas corpus has not been suspended then why should the court be ruling on who may suspend it?
If at any time the public safety should require the suspension of the powers vested by this act in the courts of the United States, it is for the legislature to say so.
And had habeas corpus been suspended then this would certainly be a definitive ruling on who may suspend it. But habeas corpus had not been suspended, so this falls under the category of an obiter dictum. Something that a future judge could quote in support of a future ruling if habeas corpus ever was suspended, but not in and of itself a binding legal decision.
[ns] If habeas corpus has not been suspended then why should the court be ruling on who may suspend it?
If it has been suspended, the court cannot proceed to hear the case. Most courts consider jurisdiction an important issue. In Texas v. White the court ruled on secession to determine jurisdiction. By your logic, if secession had not occurred, then the issue was not before the court. That ruling must have been dictum.
Again, how are you determining, for judicial purposes, whether the power had been suspended or not?
To determine whether it has been suspended, how do you make a determination without determining WHO may suspend it?
The court concluded:
If at any time the public safety should require the suspension of the powers vested by this act in the courts of the United States, it is for the legislature to say so.That question depends on political considerations, on which the legislature is to decide. Until the legislative will be expressed, this court can only see its duty, and must obey the laws.
The motion, therefore, must be granted.
Because the question of who may suspend it was material to the case.
Heck, let's use the actual words of the Court and let's not paraphrase.
The inquiry therefore on this motion will be, whether by any statute, compatible with the constitution of the United States, the power to award a writ of habeas corpus, in such a case as that of Erick Bollman and Samuel Swartwout, has been given to this court.The preliminary question is whether the Court had the power to issue "a" writ, i.e., any power to issue such a writ at all.
The Court answered that question in the affirmative.
The 14th section of the judicial act (Laws U. S. vol. 1. p. 58.) has been considered as containing a substantive grant of this power.
The Court then addressed to whom the substantive grant of power was given:
Whatever motives might induce the legislature to withhold from the supreme court the power to award the great writ of habeas corpus, there could be none which would induce them to withhold it from every court in the United States; and as it is granted to all in the same sentence and by the same words, the sound construction would seem to be, that the first sentence vests this power in all the courts of the United States; but as those courts are not always in session, the second sentence vests it in every justice or judge of the United States.
The court then noted the suspension clause of the Constitution.
It may be worthy of remark, that this act was passed by the first congress of the United States, sitting under a constitution which had declared 'that the privilege of the writ of habeas corpus should not be suspended, unless when, in cases of rebellion or invasion, the public safety might require it.'
Having answered the general question of whether the court had the authority to issue "a" writ, it now proceeded to the more specific question of whether it could issue "the" writ requested in this case.
If, by the sound construction of the act of congress, the power to award writs of habeas corpus in order to examine into the cause of commitment is given to this court, it remains to inquire whether this be a case in which the writ ought to be granted.
And the Court proceeded to ask another question.
If the act of congress gives this court the power to award a writ of habeas corpus in the present case, it remains to inquire whether that act be compatible with the constitution.
The Court answered that question as follows:
The decision that the individual shall be imprisoned must always precede the application for a writ of habeas corpus, and this writ must always be for the purpose of revising that decision, and therefore appellate in its nature.But this point also is decided in Hamilton's case and in Burford's case.
If at any time the public safety should require the suspension of the powers vested by this act in the courts of the United States, it is for the legislature to say so.
That question depends on political considerations, on which the legislature is to decide. Until the legislative will be expressed, this court can only see its duty, and must obey the laws.
Having decided, on that stated basis, that the granting of the writ was an act compatible with the Constitution, the Court held:
The motion, therefore, must be granted.