when did senate rules change to 60 votes
1975
-1
Section::::History.:The two-track system, 60-vote rule and rise of the routine filibuster (1970 onward).

Filibuster in the United States Senate
26376415
2895734939693180581
NONE
Section::::History.:The two-track system, 60-vote rule and rise of the routine filibuster (1970 onward).

Filibuster in the United States Senate
26376415