I believe that this is basically a form of the filibuster rule that has been in place in Congress since the earliest days of the Republic. (If anyone knows any different please let me know.) Filibustering is nothing new. It has been used in the past to block opponents' attempts to enact legislation when the minority was trying to piece together enough fence sitters to stop legislation, or when they were simply trying to wear down the majority. It has been used by both parties in the past and will probably be used again in the future. (I believe that the number to stop a filibuster used to be two-thirds of the Senate, but was dropped to a simple 60 member "supermajority" in the 80's.)
That's not really the problem. The GOP does not want to take away the filibuster as a legitimate parliamentary tool. Instead, they want to limit it to what it was originally for.
After Bush took office in 2000 the Dems used the filibuster for the first time ever to block judicial nominees. That was really unprecedented and was considered a nuclear option when it was first used. The press would have gone NUTS if the GOP had done this - calling them obstructionists, mean-spirited, et al. - but they uttered nary a peep when the Dems actually started doing it.
In 2003, after the GOP won back the majority in the 2002 mid term elections, the idea of using this new nuclear option was discussed among GOP leaders. Frist threatened it a few times, but I believe that he failed to use it because he knew that it was unlikely to pass muster. Too many of the GOP Senators were RINO's and wouldn't go along with it, which would have meant that it would have gone down to defeat and the Republicans would have looked like small-minded losers in even trying to change the rules. (There was also the fear that it might backfire on them in the future if the GOP ever found itself in the minority again - something that seemed possible on November 1, 2004.)
Today things have changed. There are now 55 Republican Senators and 51 of them are pretty loyal partisans and would almost certainly vote for the change. Also, my understanding is that the rules change would only affect votes concerning Presidential nominees. Legislative action would still be governed under the same Senate rules as before.
Good brief summary of it's history here: http://www.nationalreview.com/comment/comment-eastman051503.asp
" ...Sen. Frist's proposal would effectively return to rules that prevailed in the Senate from its establishment in 1789 until 1806, by which a simply majority could end debate on a motion for the previous question and under which no one was "to speak impertinently or beside the question, superfluously or tediously." Nor is this the first time that the Senate rules have been changed to address an abusive use of the filibuster. Between 1841, when the filibuster was first utilized by Sen. John C. Calhoun to protect slaveholding interests, and 1916, when Sen. Robert LaFollette used it to block legislation that would have authorized merchant ships to arm themselves against unlawful attacks by German U-boats before the United States entered World War I, unanimous consent was required to end a filibuster. During that time, there were nearly a dozen proposals to restore the "motion for the previous question" rule or a cloture rule, but Sen. LaFollette's filibuster was the last straw: In 1917, the Senate adopted the first cloture rule, providing that debate could be ended by a vote of 2/3 of the senators present and voting.
When that rule began to be abused by the use of a filibuster to block procedural motions not subject to the 2/3 cloture vote (a practice that rendered the cloture option meaningless), the Senate amended its cloture rule in 1949 to extend to procedural motions, but in a compromise increased the vote required to 2/3 of the full Senate rather than 2/3 of the senators present and voting. During the 1950s, there were several attempts to reduce the number necessary to invoke cloture from 2/3 to a simply majority, and several others to provide a two-tiered cloture rule, whereby a 2/3 vote was required initially but a simply majority vote would suffice after a reasonable period for debate, between 12 and 15 days. Additional amendments were proposed during the 1960s until, in 1975, the cloture rule was amended to allow cloture by a vote of 3/5 of the Senate (today's 60-vote requirement). Finally, in 1995, Sen. Harkin proposed to establish a declining vote requirement for cloture, so that by the 4th cloture vote, a simple majority of the Senate would suffice to end debate and allow the Senate to proceed to a vote on the merits of the matter at hand."
From the notes of one of the first Senators:
" In case of a debate becoming tedious, four Senators may call for the question; or the same number may at any time move for the previous question, viz, "Shall the main question now be put?" "
This is the method still used to end debate in the House today.