Jon Meacham, a historian and biographer of President George H.W. Bush, said Wednesday that President Trump has "moved the goal posts of the civilized society," making former conservative lawmakers appear more favorable than in the past.

"The Bushes, President Reagan, Sen. [Bob] Dole [Kan.], Sen. [John] McCain [Ariz.], [former Massachusetts] Gov. [Mitt] Romney all represent a different kind of Republican," Meacham said on MSNBC's "Deadline: White House."

"The sudden sentimentality for folks whom a lot of people on the left had great disdain for many years is striking [and] ... is one sign of how far Trump has moved the goal posts of the civilized society," he continued, referring to nostalgia some on the left may have for past Republican presidents and politicians in the age of Trump. 

Meacham's comments come as Trump faces fierce backlash for his controversial comments on last weekend's violence in Charlottesville, Va. 

Trump said "both sides" — white supremacists and anti-racist counterprotesters — were to blame for the violence despite the unrest being triggered by a white supremacist rally held to protest the removal of a statue of Confederate Gen. Robert E. Lee. The ensuing violence from the two sides clashing resulted in the death of one anti-racist protester and the injury of at least a dozen more when a man with alleged white supremacist ties plowed his car into a crowd.

Republicans, including the Bushes, Romney and McCain, have spoken out against racism and violence since, contrasting themselves with Trump. 

McCain called on Trump to "defy hate and bigotry," after his Trump Tower press conference. 

Romney, the 2012 GOP presidential nominee, appeared to hit back against the president's assertion that both sides were responsible for the violence in a tweet on Tuesday.

Former President George H.W. Bush and his son, former President George W. Bush, condemned the violence in Charlottesville, saying the U.S. must reject "hatred in all forms" in a statement.