President Trump announced on Twitter Tuesday night that Christopher Krebs, the head of the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency, had been fired effective immediately.

Why it matters: Krebs, who is responsible for securing voting technology, has drawn bipartisan praise for his handling of the election and debunking of misinformation. Reuters recently reported he expected to be fired after he pushed back against false claims that Democrats "rigged" the election, a claim that Trump has heavily promoted.

Our thought bubble: Krebs is a universally respected figure even in the notoriously fractious world of cybersecurity and information security, notes Zach Dorfman, author of Axios’ Codebook newsletter.

What they're saying: "Honored to serve. We did it right. Defend Today, Secure Tomrorow. #Protect2020," Krebs tweeted Tuesday evening from his personal account following the news of his termination.

• Michael Gwin, a spokesperson for President-elect Biden, said in a statement, "Chris Krebs should be commended for his service in protecting our elections, not fired for telling the truth.
• "Bipartisan election officials in the administration itself — and around the country — have made clear that Donald Trump's claims of widespread voter fraud are categorically false and Trump's embarrassing refusal to accept that reality lays bare how baseless and desperate his flailing is."

Rep. Adam Schiff (D-Calif.), chair of the House Intelligence Committee, called Krebs' firing "pathetic, but sadly predictable."

• “Throughout this election, the CISA and Director Krebs have worked diligently to safeguard our elections, provide vital support to state and local election officials, and inform the American people about what was true and what was not. In the best tradition of government service, they spoke truth to power and helped keep Americans and our institutions safe," Schiff said in a statement.
• “Instead of rewarding this great service, President Trump is retaliating against Director Krebs and other officials who did their duty. It’s pathetic, but sadly predictable that upholding and protecting our democratic processes would be cause for firing."

The big picture: Krebs' firing signals that Trump continues to feel unshackled in the post-election period to punish officials he views as disloyal, even if it’s at the expense of his own administration’s morale and ability to function.

• Christopher Miller, director of the National Counterterrorism Center, replaced Mark Esper as acting secretary of Defense, after Trump clashed with Esper over a number of issues since the summer.
• Trump named Michael Ellis, a former aide to House Intelligence Committee ranking member Devin Nunes, who most recently served as the NSC official in charge of intelligence programs, general counsel of the National Security Agency.
• The Pentagon’s top policy official, James Anderson, resigned in anticipation of being fired by Trump. Anderson was replaced by Anthony Tata, an administration loyalist who was denied the job earlier this year after his prior bigoted comments came to light.
• Trump officials named Kash Patel, another former aide to Devin Nunes, as chief of staff to the secretary of defense.
• The Pentagon’s undersecretary of defense for intelligence was also forced to resign and replaced with Ezra Cohen-Watnick, another former NSC staffer and Trump loyalist.

Editor's note: This article has been updated with Gwin's comments.