While the overwhelming majority of Americans are pro-choice, we do not have a pro-choice majority in the US Senate -- only 37 Senators are staunchly pro-choice, while an additional 17 Senators have mixed records. Therefore, if an anti-choice Supreme Court Justice is put forward, the best strategy will be a filibuster against the nomination, which requires only 41 votes, thus forcing the President to withdraw his nominee. During a filibuster, Senators prolong debate and refuse to vote, effectively defeating the nominee. The anti-choice side needs 60 votes in the Senate to cut off debate and break a pro-choice filibuster.