The contest for California’s first U.S. Senate vacancy in 24 years has been a sleepy affair with few opportunities for voters to size up the candidates.

But the outcome isn’t a trivial matter.

Whomever is elected president, it will be the Senate’s responsibility to ratify treaties and vet Cabinet secretaries, U.S. Supreme Court justices, ambassadors and hundreds of other government officials. In recent years, the Senate also has served as a check on the hyper-partisan impulses of the House of Representatives.

Kamala Harris, a Democrat, is best suited for that role.

Harris is a career prosecutor who became district attorney in San Francisco before winning the first of her two terms as California’s attorney general.

Her opponent, Loretta Sanchez, an Orange County congresswoman, also is a Democrat.

They are running to succeed Sen. Barbara Boxer in California’s first statewide election to feature candidates from the same party, a product of the top-two primary system enacted by voters six years ago — and a reflection of a state where registered Democrats now outnumber registered Republicans by almost 2-to-1.

Even though they’re both Democrats, there are clear distinctions between the candidates, involving both policy and style.

Harris is eloquent and insightful — if a little too reluctant to get in front on potentially divisive issues and a little too willing to slant analyses on pension initiatives. Still, with her legal skills, she is well prepared for the role of questioning and assessing judicial nominees.

Harris’ record in office includes supporting programs to reduce recidivism as district attorney and, as attorney general, establishing a unit of the state Justice Department dedicated to disarming felons. She also deserves credit for breaking with fellow attorneys general and holding out for a better settlement with big banks accused of foreclosure abuses. Harris won billions in mortgage relief to underwater California homeowners and helped secure passage of added protections through a homeowner bill of rights over strong opposition from lenders.

As a senator, she says she wants to make higher education more affordable, pursue criminal justice reform and support climate change legislation.

Sanchez is as outspoken as Harris is cautious. That isn’t necessarily a bad thing. Sanchez, however, has managed to unnecessarily offend Native Americans, Muslims and blacks with unguarded remarks during her Senate campaign. And she’s shown little contrition.

The strongest argument for Sanchez is her two decades of experience in the House, with positions on the Armed Forces and Homeland Security committees and the demonstrated fortitude to cast some politically difficult votes. In the aftermath of the 9/11 attacks, she opposed the USA Patriot Act and going to war in Iraq. But her attendance has been spotty, and her legislative record is thin.

Harris still needs to illuminate her views on, among other things, water and fisheries issues critical to the North Coast. But she has the potential to be an effective leader in Washington, and she has our recommendation for the U.S. Senate.