Former colleague Brit Hume on Sam Donaldson's Bloomberg endorsement: 'Never thought I'd see this'

Brit Hume, who once served as a White House correspondent for ABC News, said he "never thought" he would see his former colleague Sam Donaldson endorse a political candidate after the longtime journalist announced his support for 2020 Democratic White House hopeful Michael Bloomberg.

Donaldson, 86, served as ABC's White House correspondent from 1977 to 1989, before Hume, who is currently with Fox News, was awarded the job. Donaldson is best known for his clashes with former President Reagan during his two terms in the 1980s.

In addition to announcing his endorsement of Bloomberg during an interview with CNN's Anderson Cooper on Friday night, the retired newsman also did an endorsement video for the former New York City mayor and billionaire's campaign that was released on Saturday.

"We are in the grip ... of a sick, ignorant man," Donaldson, a staunch critic of President Trump throughout his first three years in the White House, told Cooper on Friday.

"He's mean, he's corrupt and if we don't get this right, we may lose the things that have made this country the best place to live in the world and that shining city on a hill that Ronald Reagan used to talk about that was the envy of the world," Donaldson added.

Donaldson's endorsement was also criticized by journalist Emily Miller, who once worked under Donaldson at ABC News.

"I am really thrown off by seeing Sam Donaldson -- my former boss @ABC -- doing a political ad," Miller wrote. "This hurts all working reporters who are trying to prove to the public they aren't all liberal and biased."

Bloomberg has been surging in the polls, leapfrogging Democratic 2020 rivals such as Sen. Elizabeth Warren (D-Mass.) and former South Bend, Ind., Mayor Pete Buttigieg to land in third place behind Sen. Bernie Sanders (I-Vt.) and former Vice President Joe Biden, who has slipped considerably in recent weeks, in some recent national polls.