Senate Democrats are urging President Trump to back down from a threat to veto a mammoth defense bill over a provision that would require the Pentagon to rename bases named after Confederate figures. 

Several Democrats — including Democratic Leader Charles Schumer (N.Y.) and Sens. Elizabeth Warren (Mass.) and Jack Reed (R.I.), the top Democrat on the Armed Services Committee — sent a letter to Trump on Thursday saying they were "deeply troubled" by his tweet saying that he will "not even consider" renaming the bases. 

"As President and Commander-in-Chief, we urge you to stand on the right side of history and support the SASC-adopted proposal to remove all names, symbols, displays, monuments, and paraphernalia that honor or commemorate the Confederacy from bases and other property of the U.S. military," they wrote in the letter. 

In addition to Schumer, Warren and Reed, Democratic Sens. Jeanne Shaheen (N.H.), Kirsten Gillibrand (N.Y.), Richard Blumenthal (Conn.), Mazie Hirono (Hawaii), Tim Kaine (Va.), Martin Heinrich (N.M.), Gary Peters (Mich.), Tammy Duckworth (Ill.) and Doug Jones (Ala.) signed the letter. 

The Senate Armed Services Committee agreed to include an amendment from Warren to the National Defense Authorization Act (NDAA) that would require the Pentagon to rename bases and other military assets bearing the names of Confederate leaders.

The language included in the mammoth policy bill creates a commission to come up with a plan for renaming bases and other assets. At the end of three years, the Pentagon “shall” remove all names, symbols, displays, monuments and paraphernalia that honor or commemorate the Confederacy or anyone who served voluntarily in the Confederate army, a committee staffer said.

But the idea has faced backlash from Trump and the White House, where press secretary Kayleigh McEnany told reporters Wednesday that Trump would veto an NDAA that required renaming the bases.

Trump added in a tweet that "monumental and very Powerful Bases have become part of a Great American Heritage."

"Therefore, my Administration will not even consider the renaming of these Magnificent and Fabled Military Installations," he added.

But Democrats countered in their letter that Trump had a "profound misunderstanding" of the current moment in U.S. history, where the country has been rocked by days of protests after George Floyd's death. 

"Your rejection of this proposal reflects a profound misunderstanding of this moment in our nation’s history, when Americans are demanding that we reckon with a centuries-old legacy of systemic racism and our military leaders recognize that condoning Confederate symbols undermines their mission and unit cohesion," they wrote.

They added that changing the names of the bases wouldn't disrespect the military but instead address a "long-standing harm." 

"It is long past time for the United States military to cease honoring, commemorating, or otherwise celebrating those who took up arms against the United States in the Civil War, sacrificing hundreds of thousands of American lives in order to preserve the institution of chattel slavery," they added.