Watch: Reince Priebus blasts Democrats and John Lewis for questioning Trump's legitimacy

Incoming White House chief of staff Reince Priebus rebuked Democrats on Sunday who continue to lament over President-elect Donald Trump's presidential election victory and question his legitimacy.

Democratic Rep. John Lewis made headlines late last week after he said in an interview with NBC's "Meet the Press" that he doesn't view Trump as a "legitimate" president. The comments drew criticism because Democrats lectured Trump and Republicans prior to last November's election about accepting its results — no matter what.

According to Priebus, who was speaking with George Stephanopoulos on ABC's "This Week," it was very out of line for Lewis, a sitting member of Congress, to question the legitimacy of the results of America's democratic process by calling Trump "illegitimate."

In fact, Priebus labeled Lewis' comments as "disappointing" and "irresponsible."

But Stephanopoulos wasn't exactly buying Priebus' outrage. The show host went on to ask if what Lewis did in questioning Trump's legitimacy was the same as Trump questioning President Barack Obama's American birth several years ago.

Preibus was prompt to strike down the comparison, saying that questioning Obama's legitimacy and questioning the legitimacy of the American democratic process were two completely different things.

Priebus went on to explain that the "outrage" should be on Democratic congressmen like Lewis who question the American democratic process and Trump's election. That's when Priebus dropped a truth bomb.

"I think that they, including the president, should step up and get his people in line and tell them to grow up and accept the fact that they lost the election," Priebus said.

Watch the interview below: