SACRAMENTO, Calif. (AP) — U.S. Sen. Dianne Feinstein won California Gov. Jerry Brown's endorsement Tuesday in her bid for a fifth full term in Washington.

Brown, in the final year of his fourth term as governor, is the latest prominent California Democrat to line up behind Feinstein as she battles a challenge from a fellow Democrat.

State Sen. Kevin de Leon argues that Feinstein hasn't been liberal enough or stood up to Trump with enough force on immigration and other issues.

In making his endorsement, Brown offered a different take, saying Feinstein will protect health care, immigrants and the environment.

"More than ever, we need Dianne Feinstein's steady leadership in the U.S. Senate — she's exactly the right person to ensure that Trump is held accountable," he said in a statement.

Brown and Feinstein are longtime friends; Feinstein was the officiant at Brown's wedding.

De Leon spokesman Jonathan Underland said that Brown's endorsement of Feinstein wasn't surprising. He pointed to issues on which Brown and de Leon worked together at the Capitol when de Leon led the Senate, including bills on immigration, climate change and infrastructure.

"Sen. de Leon and Gov. Brown haven't known each other quite as long, though they have worked shoulder-to-shoulder on some of California's most historic measures," he said.

While many top elected Democrats are behind Feinstein, she failed to secure the endorsement of the California Democratic Party at a gathering of activists in February. De Leon did not receive the endorsement either, but earned more activist support than Feinstein.