<P> In 1975 , the Senate revised its cloture rule so that three - fifths of sworn senators ( 60 votes out of 100 ) could limit debate , except for changing Senate rules which still requires a two - thirds majority of those present and voting to invoke cloture . However , by returning to an absolute number of all Senators ( 60 ) rather than a proportion of those present and voting , the change also made any filibusters easier to sustain on the floor by a small number of senators from the minority party without requiring the presence of their minority colleagues . This further reduced the majority 's leverage to force an issue through extended debate . </P>
<P> In 1975 , the Senate revised its cloture rule so that three - fifths of sworn senators ( 60 votes out of 100 ) could limit debate , except for changing Senate rules which still requires a two - thirds majority of those present and voting to invoke cloture . However , by returning to an absolute number of all Senators ( 60 ) rather than a proportion of those present and voting , the change also made any filibusters easier to sustain on the floor by a small number of senators from the minority party without requiring the presence of their minority colleagues . This further reduced the majority 's leverage to force an issue through extended debate . </P>
when did senate rules change to 60 votes
when did senate rules change to 60 votes
1975
1975