“RULES OF PROCEDURE AND PRACTICE IN THE SENATE WHEN SITTING ON IMPEACHMENT TRIALS [Revised pursuant to S. Res. 479, 99–2, Aug. 16, 1986]”
Sections 122 through 123: change “vote” to “vote by secret ballot”.
In our current political environment, the removal of a President would best be resolved by concealing the votes of Senators. Their position on this particular national issue that will have a great impact on their re-election and national security must be free of showmanship, favoritism, and the threat of reprisal.