U.S. civil rights activists vowed on Saturday to defend hard-fought gains in voting rights and criminal justice during the presidency of Donald Trump, kicking off a week of protests ahead of the Republican's inauguration.

About 2,000 mostly black protesters ignored steady rain to march and rally near Washington's Martin Luther King Jr. Memorial, as speakers urged them to fight for minority rights and President Barack Obama's signature health care law, which Trump has vowed to dismantle.

The Rev. Al Sharpton, the rally's organizer and a veteran civil rights leader, said Democrats in Congress needed to be sent a simple message: "Get some backbone."