First Read is a morning briefing from Meet the Press and the NBC Political Unit on the day's most important political stories and why they matter.

Tillerson vs. the GOP Hawks -- A fight that will Define Trump’s Early Presidency

This morning, Donald Trump officially announced ExxonMobil CEO Rex Tillerson to be his secretary of state pick. And that move has triggered a fight that could define Trump’s first few months in office -- between Team Trump and Senate Republican hawks (John McCain, Lindsey Graham, Marco Rubio) over the issue of Russia.

Indeed, by tapping Tillerson (who was awarded Russia’s “Order of the Friendship” honor in 2013, and who opposed the U.S.-led sanctions against Russia for its intervention in Crimea), Trump has made this confirmation fight a referendum on this very issue. Tillerson’s confirmation probably wouldn’t be a problem under any other incoming president, or if Russia’s intervention in the 2016 election (and Trump’s denial of it) wasn’t the story it has become.

But here we are, and the result is Trump picking a fight with a key part of his own party -- something that we never saw Barack Obama do at this same point in time. And when you pick a high-profile fight like this, you better win.

How the CIA Concluded that Russians Were Trying to Help Trump

Meanwhile, NBC’s Ken Dilanian and Pete Williams have more on Russia’s involvement in the 2016 presidential election. “The CIA's assessment that the Russians favored Trump was not based on any single piece of new intelligence, officials briefed on the matter told NBC News. Instead, it was the result of more stringent analysis of a growing body of circumstantial evidence more detailed than anything the public has seen.

Human sources, communications intercepts and other intelligence have allowed analysts to piece together the identities of some of the players, and the steps they took to hurt Clinton's candidacy while boosting Trump's, officials said. The CIA also noted that while Russian hackers gathered information on Republicans, they didn't release any of it, the way they did with Democratic emails leaked to WikiLeaks.

The Republican National Committee denies its systems were hacked, but the emails of individual Republicans were collected — something NBC News reported in October. The FBI believes the Russians didn't find anything explosive in the Republican material they obtained, the official said, although it's not clear whether any U.S. agency knows the full extent of what data Russian hackers were able to steal.”

Trump vs. the Ethics Watchdogs

Tillerson vs. the Senate GOP hawks (over Russia) isn’t the only story that the last 12 hours have produced. Here’s another one: Trump vs. the ethics watchdogs. Last night, the president-elect fired off three tweets:

Even though I am not mandated by law to do so, I will be leaving my busineses before January 20th so that I can focus full time on the...... — Donald J. Trump (@realDonaldTrump) December 13, 2016

Presidency. Two of my children, Don and Eric, plus executives, will manage them. No new deals will be done during my term(s) in office. — Donald J. Trump (@realDonaldTrump) December 13, 2016

I will hold a press conference in the near future to discuss the business, Cabinet picks and all other topics of interest. Busy times! — Donald J. Trump (@realDonaldTrump) December 13, 2016

But as we’ve written before, Trump handing over his business to his sons doesn’t eliminate conflicts of interest or concerns about the Constitution’s Emoluments clause (which states that no person holding office shall accept any compensation from a foreign state). After all, there’s nothing to stop a foreign government from holding a lavish party at the DC Trump hotel -- which has already happened after Trump’s presidential win.

FYI: These Trump tweets are in lieu of his previously scheduled news conference, which was set for Thursday. Him promising to hold a press conference “in the near future” appears to be another kick-the-can to delay speaking to the reporters who are covering him.

Keith Ellison vs. Tom Perez

And here’s one more fight that developed in the last 12 hours -- between Keith Ellison and Tom Perez (and two others) over who will be the next chair of the Democratic National Committee. And this will be a proxy fight between Obama/Clinton World and Bernie Sanders World. “Labor Secretary Thomas E. Perez has told three senior Democrats that he intends to run for chairman of the Democratic National Committee, challenging the front-running candidate, Representative Keith Ellison, and inserting an ally of President Obama into the contest to rebuild a bruised party,” the New York Times’ Jonathan Martin writes. “Mr. Perez’s entry into the race could start a proxy battle between Democrats loyal to the Mr. Obama and those from the more liberal wing of the party represented by Senator Bernie Sanders of Vermont, who is backing Mr. Ellison, a Minnesota progressive, for party chairman.” Speaking of Sanders, don’t miss the town hall that he participated in with MSNBC’s Chris Hayes.

Oops, I Did it Again

Finally, NBC’s Hallie Jackson and Kristen Welker reported that former Texas Gov. Rick Perry has been tapped to be Energy secretary -- which just happens to be the department Perry forgot about in that 2011 “Oops” moment. Here is our running list of possible candidates we’ve been hearing about so far. We’ll continue to update it as the president-elect’s team makes its choices final.