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...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").
The Framers labored over the question of where the impeachment power should lie. Significantly, in at least two considered scenarios the power was placed with the Federal Judiciary. See 1 Farrand 21-22 (Virginia Plan); id., at 244 (New Jersey Plan). Indeed, James Madison and the Committee of Detail proposed that the Supreme Court should have the power to determine impeachments. See 2 id., at 551 (Madison); id., at 178-179, 186 (Committee of Detail). Despite these proposals, the Convention ultimately decided that the Senate would have "the sole Power to try all Impeachments." Art. I, § 3, cl. 6. According to Alexander Hamilton, the Senate was the "most fit depositary of this important trust" because its Members are representatives of the people. See The Federalist No. 65, p. 440 (J. Cooke ed. 1961). The Supreme Court was not the proper body because the Framers "doubted whether the members of that tribunal would, at all times, be endowed with so eminent a portion of fortitude as would be called for in the execution of so difficult a task" or whether the Court "would possess the degree of credit and authority" to carry out its judgment if it conflicted with the accusation brought by the Legislature-the people's representative. See id., at 441. In addition, the Framers believed the Court was too small in number: "The awful discretion, which a court of impeachments must necessarily have, to doom to honor or to infamy the most confidential and the most distinguished characters of the community, forbids the commitment of the trust to a small number of persons." Id., at 441-442.
There are two additional reasons why the Judiciary, and the Supreme Court in particular, were not chosen to have any role in impeachments. First, the Framers recognized that most likely there would be two sets of proceedings for individuals who commit impeachable offenses-the impeachment trial and a separate criminal trial. In fact, the Constitution explicitly provides for two separate proceedings. See Art. I, § 3, cl. 7. The Framers deliberately separated the two forums to avoid raising the specter of bias and to ensure independent judgments:
"Would it be proper that the persons, who had disposed of his fame and his most valuable rights as a citizen in one trial, should in another trial, for the same offence, be also the disposers of his life and his fortune? Would there not be the greatest reason to apprehend, that error in the first sentence would be the parent of error in the second sentence? That the strong bias of one decision would be apt to overrule the influence of any new lights, which might be brought to vary the complexion of another decision?" The Federalist No. 65, p. 442 (J. Cooke ed. 1961).
Certainly judicial review of the Senate's "trial" would introduce the same risk of bias as would participation in the trial itself.
Second, judicial review would be inconsistent with the Framers' insistence that our system be one of checks and balances. In our constitutional system, impeachment was designed to be the only check on the Judicial Branch by the Legislature. On the topic of judicial accountability, Hamilton wrote:
"The precautions for their responsibility are comprised in the article respecting impeachments. They are liable to be impeached for mal-conduct by the house of representatives, and tried by the senate, and if convicted, may be dismissed from office and disqualified for holding any other. This is the only provision on the point, which is consistent with the necessary independence of the judicial character, and is the only one which we find in our own constitution in respect to our own judges." Id., No. 79, at 532-533 (emphasis added).
Judicial involvement in impeachment proceedings, even if only for purposes of judicial review, is counterintuitive because it would eviscerate the "important constitutional check" placed on the Judiciary by the Framers. See id., No. 81, at 545. Nixon's argument would place final reviewing authority with respect to impeachments in the hands of the same body that the impeachment process is meant to regulate.
Nevertheless, Nixon argues that judicial review is necessary in order to place a check on the Legislature. Nixon fears that if the Senate is given unreviewable authority to interpret the Impeachment Trial Clause, there is a grave risk that the Senate will usurp judicial power. The Framers anticipated this objection and created two constitutional safeguards to keep the Senate in check. The first safeguard is that the whole of the impeachment power is divided between the two legislative bodies, with the House given the right to accuse and the Senate given the right to judge. Id., No. 66, at 446. This split of authority "avoids the inconvenience of making the same persons both accusers and judges; and guards against the danger of persecution from the prevalency of a factious spirit in either of those branches." The second safeguard is the two-thirds supermajority vote requirement. Hamilton explained that "[a]s the concurrence of two-thirds of the senate will be requisite to a condemnation, the security to innocence, from this additional circumstance, will be as complete as itself can desire." Ibid.