A controversy is nonjusticiable-i. e., involves a political question-where there is "a textually demonstrable constitutional commitment of the issue to a coordinate political department; or a lack of judicially discoverable and manageable standards for resolving it .... " Baker v. Carr, 369 U. S. 186, 217 (1962)...
In this case, we must examine Art. I, § 3, cl. 6, to determine the scope of authority conferred upon the Senate by the Framers regarding impeachment. It provides:
"The Senate shall have the sole Power to try all Impeachments. When sitting for that Purpose, they shall be on Oath or Affirmation. When the President of the United States is tried, the Chief Justice shall preside:
And no Person shall be convicted without the Concurrence of two thirds of the Members present."
The language and structure of this Clause are revealing. The first sentence is a grant of authority to the Senate, and the word "sole" indicates that this authority is reposed in the Senate and nowhere else....
Petitioner devotes only two pages in his brief to negating the significance of the word "sole" in the first sentence of Clause 6. As noted above, that sentence provides that "[t]he Senate shall have the sole Power to try all Impeachments." We think that the word "sole" is of considerable significance. Indeed, the word "sole" appears only one other time in the Constitution-with respect to the House of Representatives' "sole Power of Impeachment." Art. I, § 2, cl. 5 (emphasis added). The commonsense meaning of the word "sole" is that the Senate alone shall have authority to determine whether an individual should be acquitted or convicted. The dictionary definition bears this out. "Sole" is defined as "having no companion," "solitary," "being the only one," and "functioning ... independently and without assistance or interference." Webster's Third New International Dictionary 2168 (1971). If the courts may review the actions of the Senate in order to determine whether that body "tried" an impeached official, it is difficult to see how the Senate would be "functioning ... independently and without assistance or interference."...
The history and contemporary understanding of the impeachment provisions support our reading of the constitutional language. The parties do not offer evidence of a single word in the history of the Constitutional Convention or in contemporary commentary that even alludes to the possibility of judicial review in the context of the impeachment powers. See 290 U. S. App. D. C., at 424, 938 F. 2d, at 243; R. Berger, Impeachment: The Constitutional Problems 116 (1973). This silence is quite meaningful in light of the several explicit references to the availability of judicial review as a check on the Legislature's power with respect to bills of attainder, ex post facto laws, and statutes. See The Federalist No. 78, p. 524 (J. Cooke ed. 1961) ("Limitations ... can be preserved in practice no other way than through the medium of the courts of justice")...
In addition to the textual commitment argument, we are persuaded that the lack of finality and the difficulty of fashioning relief counsel against justiciability. See Baker v. Carr, 369 U. S., at 210. We agree with the Court of Appeals that opening the door of judicial review to the procedures used by the Senate in trying impeachments would "expose the political life of the country to months, or perhaps years, of chaos." 290 U. S. App. D. C., at 427, 938 F. 2d, at 246. This lack of finality would manifest itself most dramatically if the President were impeached. The legitimacy of any successor, and hence his effectiveness, would be impaired severely, not merely while the judicial process was running its course, but during any retrial that a differently constituted Senate might conduct if its first judgment of conviction were invalidated. Equally uncertain is the question of what relief a court may give other than simply setting aside the judgment of conviction. Could it order the reinstatement of a convicted federal judge, or order Congress to create an additional judgeship if the seat had been filled in the interim? (emphasis added)
