Unlike the San Jose Mercury News, which championed Dolores Carr’s opponent four years ago and has been unrelenting in its criticism of her ever since, Metro endorsed Carr in the 2006 general election. We believed an outsider would be healthy for an office with a succession process as ingrown and medieval as the Vatican’s papal conclave.

Sadly, her troubled tenure has been plagued by rookie mistakes, judgment lapses and a tin ear for the appearance of conflicts of interest. And despite the edge she now holds in managing a county department, we’ve concluded that the less experienced Jeff Rosen will grow into the job faster than it will take Carr to repair the county’s damaged prosecutorial apparatus and restore its reputation.

Carr tripped early on by appointing a judge as her chief assistant, which is constitutionally prohibited. She showed no interest in pursuing two high-profile political corruption cases (one of which involved her campaign treasurer’s brother-in-law) left behind by her predecessor, George Kennedy. Then, when a political operative aligned with Cindy Chavez hacked into City Hall email systems to smear the South Bay Labor Council’s political opponents, Carr chose not to follow the trail upstream.

She similarly took a pass when she had the opportunity to protect the safety of a deputy DA when SBLC-funded bloggers published a map to the gang prosecutor’s family home. In each case, legal arguments supported her decision, though they conveniently favored one political faction, with whom Carr had cozied herself.

Carr also sent deputy DA JoAnne McCracken to San Jose City Hall to argue against an open government ordinance at Sunshine Reform Task Force meetings. She intervened in cases on behalf of defendants represented by attorneys who funded her campaign. And when her husband’s paid consulting work conflicted out her office in a murder case, she seemed slow to understand what the fuss was about.

Her opponent, Jeff Rosen, is a smart, tough and thoughtful homicide prosecutor whose Obama-esque rise from obscurity demonstrates, at minimum, the energy, persuasion and multitasking competence that leadership requires. He wants to put the bad guys in jail while expressing a desire to exercise discretion on the victimless activities that force too many people into the justice system these days.

Former district attorney Kennedy and House Judicial Committee member Zoe Lofgren, who was mentioned as a Supreme Court Justice candidate, have both endorsed Rosen. Their confidence in his capabilities, in addition to the support of the many deputies who work alongside him, should reassure voters that Jeff Rosen deserves a chance to be the county’s next district attorney.