There are no good choices in the campaign to replace state Sen. Ellen Corbett in the East Bay district stretching from Hayward to the north side of San Jose.

We disagree with Assemblyman Bob Wieckowski, D-Fremont, more often than we agree with him, but he's the only candidate worthy of consideration in the five-candidate field.

First consider the alternatives: There's former Assemblywoman Mary Hayashi, D-Castro Valley, a convicted shoplifter who still won't admit she stole $2,450 worth of clothing from San Francisco's Neiman Marcus.

She pleaded no contest, remains on probation, says she erred, but won't explain why or what happened. She says she's trying to get past this; actually, she's trying to make it go away. There's a big difference.

Her spokesman first suggested the incident was a misunderstanding. It wasn't. Store personnel already had her in their sights because of suspected past shoplifting. This time she got caught.

Full disclosure provides the only path to personal or political redemption. Until Hayashi explains her actions, voters shouldn't consider her.

Then there's chameleon Audie Bock, a Green Party member when she won an Assembly seat on a fluke in a 1999 special election, only to re-register as an independent and lose re-election.

She later re-registered as a Democrat before switching again to independent. What does she now stand for? Who knows? She refused to participate in candidate interviews.

As for Democrat Roman Reed and Peter Kuo, the race's only Republican, they seem like deer caught in the political headlights. Reed maintains the answer to every state budget problem lies in revenues from stem-cell research. Kuo seeks to solve the state's water puzzle with desalinization and no regard for the health of the Delta.

Which brings us to Wieckowski. He's smart and articulate. For example, he mastered details of the severe state teachers' pension plan underfunding, and supports a reasonable solution.

Unfortunately, he's wrong on so many other issues. He inappropriately meddled in last year's BART labor dispute and has consistently put union interests ahead of all else.

In 2012, he led a failed effort to block local governments from seeking bankruptcy protection. After agreeing to a compromise, he immediately pushed for more obstacles. It was intellectually dishonest and demonstrated an inability to keep a promise.

In 2013, he authored legislation that would have tightly restricted state courts' ability to contract out some work to cope with budget cuts. Fortunately, the governor vetoed the bill.

Wieckowski is the best-informed candidate. So, by default, we swallow hard as we endorse him for the District 10 seat in the state Senate.