The Note: John Kelly takes command, but can Trump control himself?

— -- WHAT YOU NEED TO KNOW TODAY

THE TAKE with ABC News' Rick Klein

This is one of those moments, in normal times, that would mark a strategic reset. These are not normal times. John Kelly assumes the role of White House chief of staff this morning, bringing his military and homeland security credentials to an institution that craves discipline and structure. This he might achieve. But while Kelly inherits the baggage of staff infighting and rivalries, mostly he inherits the man who still seems to relish the chaos. President Trump has escalated his wars on, well, everybody – friends and foes, loyalists and lobbyists, Democrats and Republicans, Congress and his own executive branch. Trump finds himself at the low point of his influence, and raging even at those who continue to demonstrate loyalty. It would be a natural time to end the soap opera and concentrate on governing. But Trump, as always, appears to enjoy the show.

QUOTE OF THE DAY

"In the White House's view, they can't move on in the Senate....They should stay and work and figure out a way to solve this problem." -- OMB Director Mick Mulvaney to CNN's Jake Tapper on whether the Senate should consider other votes beside health care.

WHAT TO WATCH TODAY

John Kelly is sworn in as the White House chief of staff at 9:30 a.m.

Following that, Trump leads his second full Cabinet meeting at 10 a.m.

President Trump will present the Medal of Honor to 71-year-old Vietnam veteran and former Army medic Jim McCloughan.

"THE BRIEFING ROOM." After every White House press briefing - on camera or not - ABC News' political team will have full coverage and analysis from Political Director Rick Klein, correspondents Jonathan Karl, Cecilia Vega, Mary Bruce and others. Catch us on "The Briefing Room" at the ABC News Politics Facebook page, the ABC News YouTube page, ABCNews.com/LIVE and the ABC News app.

NEED TO READ with ABC News' Daksha Sthipam

Trump won't let Obamacare "implode," health secretary says. Health and Human Services Secretary Tom Price would not concede that President Trump intends to let "Obamacare implode," despite Trump's promise to do just that. "The president's passion about this is that he understands that this system may be working for Washington. It may be working for insurance companies. But it's not working for patients. And that's where his passion is," Price told ABC News' "This Week" on Sunday. http://abcn.ws/2v8X4c9

Trump's new chief of staff needs to "protect" Russia investigation, Democrat says. President Trump's new White House chief of staff has "got to protect" the Russia investigation from "continued assault" by the president, said former Hillary Clinton campaign chair John Podesta. On "This Week," Podesta stressed that Trump's new chief of staff, Ret. Gen. John Kelly, is responsible for safeguarding the Justice Department from interference. http://abcn.ws/2uOvUV2

Mike Pence arrives in Estonia, kicking off Eastern Europe trip. Vice President Mike Pence and second lady Karen Pence arrived in Estonia Sunday afternoon, kicking off a three-country visit of Eastern Europe. The Pences, who left from Joint Base Andrews in Maryland Saturday, were greeted at the Tallinn airport by U.S. ambassador to Estonia James D. Melville and Estonian Minister of Foreign Affairs Sven Mikser. http://abcn.ws/2tTZv2r

Russia's retaliation to US actions "long, long overdue," Kremlin says. Russia's deputy foreign minister said his country's retaliation over U.S. actions against Russia was "overdue" and that the Kremlin will consider "symmetrical or asymmetrical" responses to new sanctions passed by Congress. Deputy Foreign Minister Sergei Ryabkov said on "This Week" that Congress' vote was the "last drop." http://abcn.ws/2hduQqS

WHO'S TWEETING?

@Kyle_Feldscher: Kellyanne Conway: Trump will decide next week if administration will make Obamacare cost-sharing payments http://washex.am/2vkMoHD

@_RoxanneRoberts: Joe Biden thinks he would have beaten Donald Trump in 2016. Could he do it in 2020? Let's talk about "what if?" http://wapo.st/2vdRx3w

@TimAlberta: The ballad of @Reince: "We don't get to pick the nominee. And we don't get to just walk away from him, either." http://politi.co/2eYReUe

@DanielleEGaines: Finally official: John Delaney will retire from Congress, run for the presidency in 2020 #md06 #mdpolitics

@BennyHutch: At #Cubs #Brewers game. #ChrisChristie was getting razzed by fans, so he got in the face of one of them. 5:30 on @WISN12News http://bit.ly/2vkyMfA

The Note is a daily ABC News feature that highlights the key political moments of the day ahead. Please check back tomorrow for the latest.