President-elect Donald Trump picked the Martin Luther King Jr. holiday weekend to slam civil rights icon Rep. John Lewis, D-Atlanta, as "all talk" in a tweet after Lewis said he did not view Trump as a "legitimate president" because of Russia's reported interference in the election.

In doing so, Trump did little to counter arguments that he is a racist whose administration is riddled with white supremacists.

Lewis was a leader in the civil rights movement of the 1960s, who was nearly beaten to death fighting Jim Crow laws.

In a pair of tweets, Trump implied that Lewis was not doing enough work for his own constituents and should reexamine his priorities.

Critics were quick to question Trump's judgment in making the tweets, given all the things that are on his plate right now, including preparing a speech for an inauguration that is less than a week away.

Journalist Dan Rather took to Facebook to call out Trump's statements, which he said couldn't be ignored without normalizing such inappropriate attitudes.

"[John Lewis] came within a hair's [breadth] of dying after being beaten by Alabama State Troopers on a march across the Edmund Pettus Bridge in Selma," Rather said, calling Lewis "a true American hero."

Lewis had only days prior testified against Trump's pick for attorney general, Sen. Jeff Sessions, bringing to bear his civil rights bona fides.

The president-elect's tweets are sure to rile Democrats and members of the Congressional Black Caucus and even some Republicans are coming out against him for it.

But there's little confidence that Trump will moderate his tweeting habits once he inherits the @POTUS Twitter account.