Where in the constitution can i find the margin required to elevate a presidents nominee to a seat on the court?

2 answers

http://topics.law.cornell.edu/constitution

Article II, Section 2.
Article II, Section 2 specifies that the Senate must approve these nominations. Since it doesn't specify, it's always been by a simple majority.

http://en.wikipedia.org/wiki/Appointment_and_confirmation_to_the_Supreme_Court_of_the_United_States

http://caselaw.lp.findlaw.com/data/Constitution/article02/