By MICHAEL FALCONE ( @michaelpfalcone )

NOTABLES

• FEDS INVESTIGATING CHRISTIE'S USE OF SANDY RELIEF FUNDS. New Jersey Gov. Chris Christie, viewed by many as a hero of Superstorm Sandy, is now facing a federal investigation into his use of millions in money his administration received as part of a massive recovery package, according to ABC's JOSH MARGOLIN. Rep. Frank Pallone, D-N.J., said this morning he was notified "at the end of last week" that a preliminary review by the inspector general of the Housing and Urban Development Department has now become "a full-blown investigation." "There's reason to believe there's a problem here," Pallone said. At issue is $25 million used for the controversial "Stronger than the Storm" advertising campaign, which starred Christie and his family right as the governor was running for a second term. http://abcn.ws/1hhVZPw

• MORE SUBPOENAS EXPECTED OVER BRIDGE SCANDAL: Legislative subpoenas could be served to the aides of New Jersey Gov. Chris Christie as early as today sources told ABC News. Christie has been under intense political scrutiny after it was revealed that some of his top political aides shut down key traffic lanes on the George Washington Bridge - the busiest bridge in the world - in September for what appear to be politically motivated reasons. Christie has denied any knowledge of the motivation behind the lane closures and so far no evidence has been shown that he knew about the reason for the lane closures. Complicating matters for investigators is the fact that the legislative session is scheduled to end on Tuesday, which could mean a legislative subpoena issued today would expire tomorrow. A special legislative session has been scheduled on Thursday to vote on extending the investigative probe. Some Democratic lawmakers are saying that Christie could face impeachment hearings if it turns out he knew about the lane closures and authorized them. http://abcn.ws/1eNmxWG

THE ROUNDTABLE

ABC's RICK KLEIN: "Completely at risk." That was Rudy Giuliani's judgment of where Gov. Chris Christie's political career would be left if his "blanket denial" of knowing about the bridge scandal turns out to be less than accurate. That's Giuliani helping a friend. And yet, there are enough question marks lingering to give those words the potential to sting. Most troubling for Christie and his allies is that the whole mess still doesn't make sense. Someone thought that snarling traffic in a particular town made sense as a form of retribution against somebody. There are deeper levels to the motivation, the planning, and the cover-up stories - and multiple state and federal investigations to get to the bottom of it all. The Christie scrutiny has only begun.

ABC's JEFF ZELENY: It's another buckle-your-seatbelt kind of week for Gov. Chris Christie. The around-the-clock analysis of his political future shows little sign of easing, particularly as he delivers his State of the State address Tuesday in Trenton. But the probe into the bridge closing scandal will continue long after. Inside his inner circle, there is still high tension, with aides bracing for more details to be revealed. Christie survived the first test, but the coming weeks present even more skepticism and bigger challenges as legislative subpoenas are handed out and a hungry pack of investigative reporters dig in. His prospects for 2016 remain alive, of course, and he's hardly the only GOP contender who faces hurdles. But it's hard to imagine he'll ever be able to fully shake the rap that he's just another politician, which was never one of his obstacles.

ABC's SHUSHANNAH WALSHE: New Jersey Gov. Chris Christie has kept quite a low profile since his almost two hour press conference where he apologized repeatedly and said he had no idea his aides had shut down lanes to the world's busiest bridge for political pay back. But, tomorrow that changes. Facing his constituents, as well as the traditional group of state lawmakers, lobbyists and press, Christie will give his State of the State. Last year the focus was how much the state had recovered in the months since superstorm Sandy and how much farther they had to go. It is likely the state's recovery will be a large part of the address, but there is no ignoring the unfolding scandal where more subpoenas of other close aides are expected by the state Assembly as soon as this week. Does he apologize more or lay out how this kind of behavior will never happen again in a Christie administration? The whole country will be watching both for now and 2016.

BUZZ

GIULIANI: CHRIS CHRISTIE'S CAREER 'COMPLETELY AT RISK' IF HE ISN'T TELLING THE TRUTH. Yesterday on "This Week," former New York City Mayor Rudy Giuliani defended New Jersey Gov. Chris Christie, but warned that the Garden State governor is putting his political future in jeopardy should evidence surface that he had any knowledge of his aides' alleged actions in the George Washington Bridge scandal, notes ABC's BEN BELL. Christie has become embroiled in an escalating and damaging political scandal over the closing of traffic lanes from Fort Lee, N.J. to the George Washington Bridge, which resulted in major backups for days last September. Christie has denied any knowledge of his aides' alleged actions and fired a senior aide for her involvement in the affair. "He says he didn't know. I think it's pretty darn credible. He wouldn't make this blanket denial unless it's not true," Giuliani told ABC's MARTHA RADDATZ Sunday. " "If, for some reason, it's not true, the man has put his political career completely at risk if it turns out there is some evidence that he knew about it," Giuliani added. "He's taken the complete risk that his political career is over. I don't think he'd do that if there's any suggestion he knew about this." http://abcn.ws/1dny2XK

FIGHT OVER PRESIDENTIAL APPOINTMENT POWER HEADS TO SUPREME COURT. It was a judicial decision few saw coming. It has blossomed into a full-scale constitutional debate concerning the separation of powers that will play out at the Supreme Court on Monday, reports ARIANE DE VOGUE. In January 2013, a federal appeals court invalidated the president's then appointees to the National Labor Relations Board, and in the process, limited the executive's power under the "Recess Appointments Clause" of the Constitution. The clause reads: "The President shall have power to fill up all vacancies that may happen during the recess of the Senate, by granting Commissions which shall expire at the end of their next session." http://abcn.ws/1dJwwKz

-WHERE DID THE CONTROVERSY BEGIN? Back in January 2012, President Obama was frustrated with Senate inaction on his nominees to the NLRB, an independent federal agency that enforces federal labor law. The president decided to invoke his recess appointment power during what is called a "pro forma" session of Congress - that is when the Senate convenes every three days. He appointed three members to the board. Without the recess appointments the NLRB would not have had enough members to function. But critics of Obama's action claimed that the Senate was actually in session at the time, therefore no recess appointments could occur. The administration countered that the pro forma sessions were an attempt to override the president's constitutional authority to make appointments and keep the government running. It wasn't long before Noel Canning, a soft drink bottling company, objected to an adverse ruling from the NLRB and sued. The company claimed the NLRB ruling was invalid, because the appointments to the board were invalid. When the case reached the U.S. Court of Appeals for the DC Circuit, it held that recess appointments could only be made during "the" official recess between congresses. The court defined "the" recess as the one that occurs between the end of one session of Congress and the beginning of the next. The court invalidated the NLRB appointments, saying they had occurred not during a permissible "intersession" but instead in an invalid "intrasession." Finally, the court ruled that appointments could only be made for vacancies that had arisen during the recess. http://abcn.ws/1hhVZPw

IRAN NUCLEAR DEAL WILL FINALLY KICK IN. The sixth-month nuclear deal announced in November is finally ready to go into effect, Secretary of State John Kerry announced this weekend. For months, U.S. and Iranian technical negotiators have been hammering out what, exactly, each side is obligated to do over the six-month agreement. Negotiations in Geneva broke off in mid-December. But the U.S. and Iran finally do have a deal, according to ABC's CHRIS GOOD. The six-month interim agreement will kick in on Jan. 20, Kerry announced on Sunday, after the under-secretary for political affairs - the U.S. official in brokering this deal - traveled to Geneva and met with Iranian and EU counterparts on Thursday, apparently laying the groundwork for the six-month clock to at last begin ticking. "While implementation is an important step, the next phase poses a far greater challenge: negotiating a comprehensive agreement that resolves outstanding concerns about the peaceful nature of Iran's nuclear program," Kerry said in a written statement released to reporters. http://abcn.ws/1do3Yv6

IN CASE YOU MISSED IT

HIGH-PROFILE NAVAL ACADEMY SEXUAL ASSAULT CASE TAKES UNEXPECTED TURN. A high-profile U.S. Naval Academy sexual assault case took an unexpected turn last week after charges were dropped against a midshipmen accused of sexually assaulting a female classmate - a development that could throw into doubt the remaining court martial case involving a second male accused in the same incident, reports ABC's ALI WEINBERG. Defense attorneys in the remaining case say the dismissal of charges on Friday means their client's case should also be dropped. Citing insufficient evidence, Naval Academy Superintendent Vice Admiral Michael Miller dismissed the case against Midshipman Eric Graham of Eight Mile, Ala., who had been charged with sexually abusive contact against a 20-year-old female midshipman. Miller's decision was based on recommendations by military prosecutors who said they had no case against Graham because military investigators had not read him his Miranda rights before questioning him. Col. Daniel Daugherty, the military judge in the case, had earlier ruled that Graham's statements were inadmissible in court. A second midshipman, Josh Tate, of Nashville, Tenn., was accused of aggravated sexual assault in the case. Tate was set to face a court martial in February, but his lawyer, Jason Ehrenberg, told ABC News that the case has been pushed back to mid-March so Tate's legal team can adapt their case to "all the stuff developing." Ehrenberg said his client's case should also be dropped because the chief evidence against Tate - testimony made by a witness during a pre-trial hearing - had also been ruled inadmissible. http://abcn.ws/1cWd5Nq

WHO'S TWEETING?

@ABCNewsPR: Van Scott Joins ABC News as Publicity Director for "World News with Diane Sawyer" http://abcn.ws/1ah3hB5

@markknoller: By my count, of the 32 recess appointments made by Pres Obama, 22 were made during holiday or summer breaks.

@bethreinhard: Battle for bragging rights over the economy in 9 swing states Obama won but governed by GOPers seeking re-election http://njour.nl/KV184B

@BuzzFeedBen: . @evanmcsan has the outlines of coming executive action on climate http://www.buzzfeed.com/evanmcsan/white-house-lays-groundwork-for-environmental-push …

@KarlRove: ICYMI: The Emerging Conservative Effort to Help the Poor http://ow.ly/swNWS