Bill Frist should resign not only his leadership post, but also his Senate seat if the Republicans fail to pass the Bolton nomination and fail to break the Democratic judicial filibuster.
In 2004 the President won more votes than any presidential candidate in the history of the country. He increased his margin of victory in nearly all the states he won in 2000 and decreased his margin of defeat in the vast majority of the states he lost. On his coattails, the Republican Senate went from a 51-49 majority to 55-45. The central criticism of the President's leadership was his handling of the Iraq war and how it reflected on the US internationally. Claiming that the President had a mandate for his policies in light of the 2004 election results is no overstatement: James Carville himself said that's what Bush's victory meant.
Since the election, the Senate Democrats have continually tried to govern as a minority by using procedural tricks, unconstitutional methods and outright lies to scuttle both the President's "controversial" judicial nominations and his picks for his leadership and Cabinet teams. The Republicans have effectively let them by being willing dupes from Chafee, McCain, Grassley and Lugar re: judicial nomination to Voinovich and (to a much lesser degree) Murkowski on the Bolton nomination.
Why? Because the Republicans are weak-willed, weak-minded and completely undisciplined. This reflects on the Frist leadership.
Frist has two tests in the next month or so: killing the filibuster and getting Bolton affirmed regardless of what happens in the Senate Foreign Relations Committee. He has partially failed the latter because he allowed Voinovich the opportunity to shaft the President by not removing the nomination from committee consideration and just bringing it straight to the floor (which is a procedural trick he could have used).
Frist's leadership on these issues is a failure to date. If he ultimately fails on both levels, he should resign as leader. This is simple honor, something still practiced in the UK (Michael Howard resigning as Tory leader after the '05 election despite large House of Commons gains for the Tories), but is not practiced in the US (Norm Mineta and George Tenet kept their jobs after 9-11-01). Frist has no leadership ability and no chance to be president in '08 (if the Republicans nominate him, they deserve a Hillary Clinton or worse in the White House). To kick his GOP colleagues where it hurts, Frist should also threaten to resign his Senate seat if the filibusters and/or Bolton fail -- that would allow Tennessee's Democrat Governor Phil Bredesen (a potential Presidential candidate in '08) to appoint a Democrat for a Senate seat in the South.
It's Bill Frist's GOP in the Senate, if it cannot ensure a Republican President gets his nominees in place, both he and it deserve to be fired.