Imagine that two years hence, Sen. Hillary Rodham Clinton, or Sen. Barack Obama, or former Sen. John Edwards is president. She or he will be trying to fill dozens (eventually) of vacancies on federal Courts of Appeals with liberal-leaning nominees. And perhaps one or two Supreme Court vacancies as well.

If and when those nominees face Republican filibusters or other tactics to deny them floor votes, what standing will the new Democratic president have to protest? How, for example, could Obama show his own nominees to be more deserving of confirmation than former Mississippi Judge Leslie Southwick, who is under attack by Obama and other Senate Democrats simply because liberal interest groups consider him too conservative?

Southwick, who is a professionally well-qualified and personally admirable Bush nominee for the U.S. Court of Appeals for the 5th Circuit (covering Louisiana, Mississippi, and Texas), is the latest victim of a judicial confirmation process that has steadily become more degraded by partisan warfare in recent decades.

Senate Democrats’ treatment of Southwick will show whether they are so shortsighted as to provide their Republican adversaries with new precedents and excuses for a campaign to obstruct the next Democratic president’s liberal nominees, no matter how well qualified.

If "too conservative" is reason enough for Democratic senators to block a floor vote on Southwick, who is no right-wing culture warrior, then "too liberal" will be reason enough for Senate Republicans to do the same when the shoe is on the other foot.

The long-term cost to the country is that bit by bit, almost imperceptibly, more and more of the people who would make the best judges—liberal and conservative alike—are less and less willing to put themselves through the ever-longer, ever-more-harrowing gantlet that the confirmation process has become.