When Rep. George Miller earlier this year announced he would retire after 40 years in Washington, and state Sen. Mark DeSaulnier began systematically dissuading other possible candidates, we worried this election would feel more like a coronation than a policy debate.

We were right.

While DeSaulnier comes well-prepared to represent the Contra Costa congressional district, which stretches from Richmond east to Pittsburg and south to Danville, his five competitors do not. The race lacks a credible alternative.

We had hoped that this rare race for an open seat, in a district where Democrats outnumber Republicans by 2-1, would offer voters options and thought-provoking debate.

Instead, only one candidate, Tony Daysog, has elective office experience, and that's on the City Council of Alameda, which isn't in the district. One need not live in a congressional district to seek the office, but there is a political gap between the island city and Contra Costa. Daysog isn't the only drop-in candidate. Attorney Ki Ingersol hails from Fairfield.

Residency aside, Democrats Daysog, Ingersol and Cheryl Sudduth, a contracts negotiator from El Sobrante; Republican Tue Phan, a retired immigration judge from Danville; and independent Jason Ramey, a refinery worker from Concord, lack the policy depth essential for the job.

In contrast, DeSaulnier brings 23 years of public office experience, including the Concord City Council, Contra Costa board of supervisors, California Air Resources Board, Assembly and state Senate.

Along the way, he made big mistakes as he tacked from centrist Republican to hard-core labor Democrat, then recently started easing back toward the middle. Most notably, he and fellow Contra Costa supervisors in 2002 increased worker pension benefits to unaffordable levels, setting the stage for the financial squeeze the county faces today.

In Sacramento, he co-authored union-written legislation that would have expanded Contra Costa's abusive pension spiking to 19 other counties. Ignorant of his own bill, he backed away when the details were exposed and tried to fix the legislation. But he then teamed up with labor on a bill making it harder for insolvent cities to file bankruptcy.

Of late, we've seen slightly more independence from DeSaulnier. He broke from the Democratic Party majority to oppose Gov. Jerry Brown's costly high-speed rail boondoggle, spoke out about the corrupting influence of money in Sacramento, questioned BART workers' authority to strike, and led the legislative investigation into Caltrans' insular culture that contributed to the Bay Bridge bolt debacle.

We hope he takes that newfound critical thinking to Washington. If he does, he could serve the district adequately. If he does not, we can only hope for a more experienced field of candidates in two years.