Luján's announcement now brings the number of House Democrats' supporting impeachment to 123.
Rep. Ben Ray Luján (N.M.), the No. 4 House Democrat, announced Monday that he's supporting an impeachment inquiry into President Trump, making him the highest-ranking member of Speaker Nancy Pelosi's (D-Calif.) leadership team to endorse the process formally.
Luján, who's leaving the House to run for a Senate seat in 2020, said he was swayed by warnings that Russian efforts to interfere in U.S. elections has continued heading into the 2020 cycle.
Trump, he said, "has failed to act," making the launch of an impeachment inquiry a necessary step "to uncover the facts for the American people and hold this president accountable."
"The Trump presidency is creating grave national security concerns," Luján said in a statement. "Not only has he ignored the warnings that our Democracy is being targeted, but he has also actively encouraged Russian interference."