LOS ANGELES (AP) — California Senate candidate Kamala Harris was endorsed Tuesday by President Barack Obama and Vice President Joe Biden, further strengthening her front-runner status in a November contest with fellow Democrat Loretta Sanchez.

Beyond the benefit of having the president’s blessing in a state with a strong Democratic tilt, Obama’s endorsement could open a new pipeline of national campaign dollars for Harris. The biggest boost could come later, when voters tune in around Election Day, with TV advertising reinforcing the White House endorsement.

In a statement, the president called Harris “a lifelong courtroom prosecutor with only one client: the people of the state of California.”

“Kamala’s experience has taught her that if you’re going to give everybody a fair shot, you’ve got to take on the special interests that too often stand in the way of progress,” Obama said.

For Sanchez, the dual endorsements represent a blow for a candidate trying to make up ground after finishing 21 points behind Harris in the June primary.

Sanchez said in a statement that she was disappointed in Obama for picking sides in a race between two Democrats and argued that Harris lacked the experience needed in the Senate.

“I believe that California voters are deeply concerned about the entrenched political establishment which has failed to work for them. Yet, it has been clear for some time that the same political establishment would rather have a coronation instead of an election for California’s next U.S. senator,” Sanchez said.

The contest represents a historic first in California — two minority women, both Democrats, in a runoff to replace retiring Sen. Barbara Boxer.

The matchup marks the first time since voters started electing senators a century ago that Republicans will be absent from California’s general election ballot for the Senate. Under California election rules, only two candidates — the top vote-getters — advance to the November election, regardless of party affiliation.

Harris earlier established herself as the favorite of the Democratic establishment, winning the state party endorsement and snagging the support of Gov. Jerry Brown and Massachusetts Sen. Elizabeth Warren, a star of the party’s liberal wing.

With Republicans shut out of the race, and much of the Democratic establishment behind Harris, Sanchez’s chances could hinge on stitching together an unusual coalition of Hispanics, Republicans, and moderate Democrats and independents.

Harris recently reported raising about $2.8 million in the second quarter of the year, compared to just over $600,000 for Sanchez. The congresswoman had $919,000 in the bank, compared to $2.7 million cash on hand for Harris, a 3-1 margin.

Obama occasionally wades into state-level politics and the endorsements were not a surprise. Harris and the president have been friends and political allies for years. In 2013, Obama apologized to her after telling a group of wealthy donors in California that she is the “best-looking attorney general.”

Sanchez’s sharply worded statement marked a break in what has been a mostly low-key campaign.