With strong backing from the White House, Frist wants to ensure that Bush's nominees to the federal bench get "a fair up-or-down vote" on the Senate floor, with a simple majority of the 100 senators deciding the matter, instead of allowing Democrats to block nominees through filibusters, which require 60 votes to break. Republicans say filibuster threats mean that, for practical purposes, a "supermajority" of 60 votes is required to confirm the nominees, rather than the traditional 51 votes.
Rephrased, ever so slightly ...
With strong backing from the White House, Frist wants to ensure that Bush's nominees to the federal bench get "a fair up-or-down vote" on the Senate floor, with a simple majority of the 100 senators deciding the matter, instead of allowing Democrats to block nominees through refusing to vote. The Senate rule referred to as cloture requires 60 votes to get to the vote over an objection. The Democrats assert that a "supermajority" of 60 votes is required to either confirm or reject the nominees, rather than the 51 votes contemplated under the Constitution.
Were does it say that? It merely states that the Senate is to advise and consent. If the Senate wanted to, they could create rules that required 99 votes in favor of any action. Obviously we want 51 votes on a judicial up/down, but it isn't mentioned in the Constitution.