Let's see how many Republicans step up now to defend Secretary Mattis now that Trump has decided to un-person him.

— Tom Nichols (@RadioFreeTom) December 23, 2018

Mattis resignation could be the "beginning of the functional end" of Trump's presidency, Meet the Press host says https://t.co/iEi7Rf6vsR pic.twitter.com/ynYFmK6fLL

— Newsweek (@Newsweek) December 23, 2018

Active duty military approval ratings:

Mattis- 84% and just 4% disapproval
Trump- 44% approval
Trump approval with military women- 26%
Trump approval with military minorities- 29% https://t.co/JGus62EHJV pic.twitter.com/Ofit2CZH4t

— Evan Siegfried (@evansiegfried) December 23, 2018

UPDATE: Deputy Secretary of Defense, Patrick Shanahan, will assume the title of Acting Secretary of Defense starting 1/1/2019. Defense Secretary James Mattis announced his resignation last week in protest of Trump's decision to withdraw U.S. forces from Syria. pic.twitter.com/w9O8yc0QHi

— Ben Kennedy (@BenKennedyTV) December 23, 2018

Who is Patrick Shanahan? Trump forces James Mattis out early amid frustration over resignation https://t.co/16Q62cfLKv pic.twitter.com/2tIsaSDX7t

— Newsweek (@Newsweek) December 23, 2018

Amazing. “One aide said although Trump had already seen the resignation letter when he praised Mattis, the president did not understand just how forceful a rejection of his strategy Mattis had issued.” https://t.co/vYyaF9oq3N

— Mark Dubowitz (@mdubowitz) December 23, 2018

Sen. Dick Durbin said he is heartbroken that Defense Secretary Jim Mattis is leaving the Cabinet and worried for the next two years of the Trump administrationhttps://t.co/KboS4MOtCv

— POLITICO (@politico) December 23, 2018

One effect of Trump pushing Mattis now: It cuts down opportunities for the secretary to speak in an official capacity.

Mattis was due to testify before both armed services committees in January, and planned to make one last visit to meet with NATO.https://t.co/2qBd3cOGra

— Dan Lamothe (@DanLamothe) December 23, 2018

"The chaos that finally cemented Mattis’s decision to leave…confirms the worst fears of Trump’s most dire critics."

This @RadioFreeTom is what i NEEDED this morning.https://t.co/zL1rlbRbkv

— Dennis Herring (@dcherring) December 23, 2018

In light of this hour's Mattis news, reupping this from today's paper –> "A rogue presidency": The era of containing Trump is over https://t.co/vGEfWLdBMr

— Philip Rucker (@PhilipRucker) December 23, 2018

It’s not often I call something a “must read.” This is one of those rare times. You must read this.https://t.co/ovTCSg7w7T

— Laurence Tribe (@tribelaw) December 23, 2018