In a joint statement released Thursday, Democratic Reps. John Lewis and Bennie G. Thompson said that after "conversations with church leaders, elected officials, civil right activists and many citizens of our congressional districts," they have decided not to attend the opening.
"President Trump's attendance and his hurtful policies are an insult to the people portrayed in this civil rights museum," the two congressmen said in a statement. "The struggles represented in this museum exemplify the truth of what really happened in Mississippi. President Trump's disparaging comments about women, the disabled, immigrants and National Football League players disrespect the efforts of Fannie Lou Hamer, Aaron Henry, Medgar Evers, Robert Clark, James Chaney, Andrew Goodman, Michael Schwerner and countless others who have given their all for Mississippi to be a better place."
They added, "After President Trump departs, we encourage all Mississippians and Americans to visit this historic civil rights museum."
The White House said it was "unfortunate" the congressmen were skipping the event.
"We think it's unfortunate that these members of Congress wouldn't join the President in honoring the incredible sacrifice civil rights leaders made to right the injustices in our history," White House press secretary Sarah Sanders said Thursday. "The President hopes others will join him in recognizing that the movement was about removing barriers and unifying Americans of all backgrounds."
Sources told CNN that Mississippi Gov. Phil Bryant invited Trump to attend the opening of the museum several months ago. White House officials confirmed this week that he had accepted the invitation. The museum, which has been under construction since 2014, features eight galleries that focus on the years 1945 to 1976, "when Mississippi was ground zero for the national Civil Rights Movement," the website says.
Housing and Urban Development Secretary Ben Carson, who will accompany Trump on Saturday, has been encouraging the President to attend the opening, a source with knowledge of the trip told CNN's Rene Marsh. In addition to the importance of the event, Carson has encouraged Trump to go because he believes the President's visit will bring the country together.
Katie Blount, director of the Mississippi Department of Archives and History, said the department looks forward to celebrating the museum's opening.
"Though we will miss some who may not be with us on Saturday, they will be remembered also as we honor the many people whose stories are told in our two museums," Blount said.
Longtime former state Rep. Robert Moak, who is now the chairman of the Mississippi Democratic Party, told CNN Tuesday the reaction to the news that Trump was attending had not been positive.
"Is this place worthy of a presidential visit? Yeah. Is it proper with this President at this particular juncture? No," Moak said. He added that though the opening is meant to be a "special event," "Trump's visit will tamp that down."
"This is not a place for cheap political tricks. It kind of feels like that's the card the governor has deal at this time," he said.
Mississippi NAACP President Charles Hampton said it is a "very inappropriate time to invite Trump."
"I'm the same age as Trump. Trump doesn't care nothing about black folks and poor people in particular," Hampton said. "If he could, he would wipe all us right off the map."
The national NAACP also disapproved of the invitation.
"President Trump's statements and policies regarding the protection and enforcement of civil rights have been abysmal, and his attendance is an affront to the veterans of the civil rights movement. He has created a commission to reinforce voter suppression, refused to denounce white supremacists, and overall, has created a racially hostile climate in this nation," President Derrick Johnson said.
Both the Mississippi Democratic Party and the NAACP chapter in Mississippi said they had not been informed that Trump had been invited by Bryant until it was published in news reports.
Jeff Steinberg is the founder of the Sojourn to the Past, a program that educates children about the Civil Rights movement, and is attending the opening Saturday. He told CNN that Trump attending the opening of the museum was "an affront to what the Civil Rights Movement really stood for."
"For me, it is not political, it is about this person in particular, who is divisive and I think has many, many racial tendencies," Steinberg said. "I don't know anyone who thinks this is a smart move. I don't know anyone who agrees that this is a move honoring people in the civil rights movement."