When a Republican former prosecutor speaks up for someone who’s being lambasted for having represented the American Civil Liberties Union, you just might sit up and take notice.

[IMGCAP(1)]I’ve proudly served as an assistant U.S. attorney in the Northern District of California. Before that I was a prosecutor for the city and county of San Francisco. Currently, I serve as a police commissioner. And, yes, I’m a lifelong member of the Republican Party.

During my nine years as a federal prosecutor, I appeared more than 50 times before a U.S. magistrate judge in San Francisco, Edward M. Chen. Some of these cases involved violent crime and drug trafficking. Time and again, Judge Chen proved that he is a fair, balanced, impartial and supremely competent jurist. And I believe that my colleagues in the law enforcement community share my assessment of him.

Why am I serving as a character witness for Judge Chen? Last year, President Barack Obama nominated him to the U.S. District Court for the Northern District of California. While the confirmation of such a well-qualified jurist should be routine, he has been the object of outrageous attacks on his patriotism and impartiality by individuals and organizations who have never met or appeared before Judge Chen.

These attacks are unwarranted. While Judge Chen doesn’t always agree with my positions in court, he faithfully applies the rule of law and listens carefully to both sides. Contrary to what some critics suggest, Judge Chen’s former career as an advocate for the ACLU has never biased his decisions as a judge. Repeatedly, he has issued rulings contrary to arguments that he once made as a lawyer. As nine other former federal prosecutors and I wrote in a letter to the Senate Judiciary Committee supporting his nomination, he is an experienced judge who understands the distinction between personal preference and judicial obligation and who has always based his rulings —more than 300 decisions over eight years — solely on the law and on the merits of the case. At a time of several historic firsts in public service, including the first Latina Supreme Court justice, it is worth noting that Edward M. Chen would be the first Asian-American federal judge in Northern California, an area with a large and growing Asian-American population.

Judicial confirmations should be decided on the basis of the nominees’ fitness and fairness, not partisanship and political philosophy or unverified perceptions. When presidents of either party nominate qualified judges, the Senate should move expeditiously to confirm them based on their records. If Judge Chen, an experienced judge whose judicial record proves he is committed to the rule of law without bias or favor and who is widely respected by the bar that has practiced before him, isn’t qualified for the federal bench, who is?

Thomas P. Mazzucco is an attorney with Murphy Pearson Bradley & Feeney in San Francisco.

Editor’s note: The Senate Judiciary Committee approved Chen’s nomination on a party-line, 12-7, vote Thursday. No floor action has been scheduled yet.