"XI. That in the trial of any impeachment the Presiding Officer of the Senate, if the Senate so orders, shall appoint a committee of Senators to receive evidence and take testimony at such times and places as the committee may determine, and for such purpose the committee so appointed and the chairman thereof, to be elected by the committee, shall (unless otherwise ordered by the Senate) exercise all the powers and functions conferred upon the Senate and the Presiding Officer of the Senate, respectively, under the rules of procedure and practice in the Senate when sitting on impeachment trials.
Unless otherwise ordered by the Senate, the rules of procedure and practice in the Senate when sitting on impeachment trials shall govern the procedure and practice of the committee so appointed. The committee so appointed shall report to the Senate in writing a certified copy of the transcript of the proceedings and testimony had and given before such committee, and such report shall be received by the Senate and the evidence so received and the testimony so taken shall be considered to all intents and purposes, subject to the right of the Senate to determine competency, relevancy, and materiality, as having been received and taken before the Senate, but nothing herein shall prevent the Senate from sending for any witness and hearing his testimony in open Senate, or by order of the Senate having the entire trial in open Senate."
The Committee procedure described in this rule has been used only three times: the impeachments of Judges Claiborne, Alcee Hastings, and Walter Nixon. In each instance, the Committee received evidence and took testimony before making a report and recommendation to the full Senate. Whether they could have refused to do that is questionable since, on its face, the rule indicates that the Committee is required to follow the rules of procedure of the Senate when sitting on impeachment trials and those rules require the Senate to consider articles of impeachment when they are received by the Senate, it would appear that simply not acting --including not taking testimony -- may not be an option. Rather, the senate could adopt a rule, as it has in other instances, allowing for a motion to dismiss before the presentation of evidence. While no such motion has ever successfully been pursued, it is a more likely than sending it to a committee.