The best thing a Senate majority leader with presidential aspirations can do is quit. That was Bob Dole's strategy in 1996, when he resigned to run against President Clinton. And it may be part of Bill Frist's decision not to seek reelection in 2006. If so, Frist could hardly make a smarter move.
Of course, abandoning the Senate didn't exactly help Dole in the presidential election, but his campaign was beyond rescue anyway. Dole quit in part because his evident mastery of its rules left the impression that he cared more about recondite parliamentary tactics than he did about the presidency. Frist, who many speculate plans a bid in 2008, has the opposite problem. The longer he tries to run the Senate, the more he looks like a bungler whose only principle is personal advancement.
It has been a particularly bad week for Frist. It started when he was outmaneuvered by Senate moderates in his effort to ram through the "nuclear option" and ban judicial filibusters. As this page has noted, Frist was right to try to get rid of the filibuster. But the defection of seven members of his own party, who joined with seven Democrats to reach a compromise on judicial nominations and leave the filibuster intact, didn't reflect well on his leadership skills.