Dems say Mattis's departure is 'scary' and 'bad news'

News of Defense Secretary James MattisJames Norman MattisShanahan drama shocks Capitol Hill, leaving Pentagon rudderless Top nuclear official quietly left Pentagon in April Top nuclear official quietly left Pentagon in April MORE's departure from the Trump administration was met with bipartisan shock and concern on Thursday.

Mattis announced he would resign at the end of February, writing in his resignation letter to President Trump that he deserved a secretary "whose views are better aligned with yours."

Sen. Amy KlobucharAmy Jean KlobucharDemocrats detail new strategy to pressure McConnell on election security bills Democrats detail new strategy to pressure McConnell on election security bills Biden, Sanders to be center stage at first debate MORE (D-Minn.) tweeted that she has "a lot of respect for General Mattis and after what happened yesterday the resignation is sadly understandable," referring to Trump's decision to withdraw U.S. troops from Syria.

House Minority Leader Nancy PelosiNancy PelosiPelosi slated to deliver remarks during panel hearing on poverty The DNC's climate problems run deep Cracks form in Democratic dam against impeachment MORE (D-Calif.) told reporters: "I’m sad. I’m shaken by it. I had so much respect for him,” according to CNN's Manu Raju.

Sen. Mark WarnerMark Robert WarnerDemocrats detail new strategy to pressure McConnell on election security bills Democrats detail new strategy to pressure McConnell on election security bills State attorneys general demand that Congress take action on election security MORE (D-Va.), vice chairman of the Senate Intelligence Committee, suggested the Trump administration would be destabilized by the Defense secretary's departure.

"This is scary. Secretary Mattis has been an island of stability amidst the chaos of the Trump administration," he wrote on Twitter. "As we’ve seen with the President’s haphazard approach to Syria, our national defense is too important to be subjected to the President’s erratic whims."

Rep. David CicillineDavid Nicola CicillineCracks form in Democratic dam against impeachment Cracks form in Democratic dam against impeachment Overnight Defense: Trump doubles down on claim Iran attacked tankers | Iran calls accusations 'alarming' | Top nuke official quietly left Pentagon | Pelosi vows Congress will block Saudi arms sale MORE (D-R.I.) called the resignation a “dire omen.”

“James Mattis was the last adult left in the room,” he tweeted. “He was maybe the last person who could tell this President 'No.' His departure is a dire omen for the future of our alliances and the security of our country.”

Mattis, a former general, was confirmed for the top Pentagon post in a 98-1 vote in the Senate; the sole dissenter was Sen. Kirsten Gillibrand (D-N.Y.).

Sen. Chris MurphyChristopher (Chris) Scott MurphyOvernight Defense: Shanahan exit shocks Washington | Pentagon left rudderless | Lawmakers want answers on Mideast troop deployment | Senate could vote on Saudi arms deal this week | Pompeo says Trump doesn't want war with Iran Senators demand Trump explain decision to deploy troops amid Iran tensions Senators demand Trump explain decision to deploy troops amid Iran tensions MORE (D-Conn.) called Thursday's news “devastating.”

“Just imagine the morale crisis at the Department of Defense right now, having sustained the 1-2 punch of the Syria reversal and Mattis resignation,” he tweeted. “Devastating.”

High-profile Republicans also expressed concern over the resignation.

Sen. Lindsey GrahamLindsey Olin GrahamOvernight Defense: Shanahan exit shocks Washington | Pentagon left rudderless | Lawmakers want answers on Mideast troop deployment | Senate could vote on Saudi arms deal this week | Pompeo says Trump doesn't want war with Iran Shanahan drama shocks Capitol Hill, leaving Pentagon rudderless Shanahan drama shocks Capitol Hill, leaving Pentagon rudderless MORE (R-S.C.) said the news filled him with "great sadness."

"It is with great sadness that I was informed of the resignation of General Mattis," he wrote. "He is one of the great military leaders in American history. He should be proud of the service he has rendered to President @realDonaldTrump and our nation."

Sen. Ben SasseBenjamin (Ben) Eric SasseSwing-state Democrats see trouble in proposed pay hike Swing-state Democrats see trouble in proposed pay hike House Dems move to give lawmakers a pay increase MORE (R-Neb.) said Mattis was important for curbing Trump’s isolationist tendencies.

“This is a sad day,” Sasse tweeted. "General Mattis was giving advice POTUS needs to hear. Mattis rightly believes that Russia & China are adversaries, and that we are at war with jihadists across the globe who plot to kill Americans. Isolationism is a weak strategy that will harm Americans...”

Sen. Marco RubioMarco Antonio RubioRubio responds to journalist who called it 'strange' to see him at Trump rally Rubio responds to journalist who called it 'strange' to see him at Trump rally Overnight Defense: US to send 1K more troops to Mideast amid Iran tensions | Iran threatens to break limit on uranium production in 10 days | US accuses Iran of 'nuclear blackmail' | Details on key defense bill amendments MORE (R-Fla.) said Mattis's resignation letter made it clear that America is headed for a "series of grave policy errors which will endanger our nation, damage our alliances & empower our adversaries."

"I hope we who have supported this administrations initiatives over the last two years can persuade the President to choose a different direction," Rubio added. "But we must also fulfill our constitutional duty to conduct oversight over the policies of the executive branch."