By MICHAEL FALCONE ( @michaelpfalcone )

NOTABLES

• ANALYSIS - ABC's JEFF ZELENY: It's the biggest legal challenge to the health care law in two years, with the Supreme Court hearing arguments today on birth control provisions in the Affordable Care Act. A central question before the justices is whether for-profit companies must provide insurance to their employees for contraception - or if business owners can say their religious beliefs are violated by the requirement. Nearly two years ago, the Supreme Court upheld a major provision of the health care law by ruling 5-4 that the individual mandate was constitutional. But could this outcome be 5-4 in favor of the corporations like Hobby Lobby, the Oklahoma-based arts-and-crafts store that is leading the challenge to the law? We won't know until the court rules in June, but may have a better sense of how the justices (many of whom are Catholic and opposed to abortion) are leaning after today's arguments.

• DISPATCH FROM THE COURT: Protesters have already gathered out front, ABC's ARIANE DE VOGUE notes. Supporters chanting: "Back off boss my health can't wait-women must decide our fate." Opponents "Hey Hey ho ho watch our freedom drift away"

BUZZ

OBAMA TO CALL FOR END TO NSA BULK DATA COLLECTION. President Obama is poised to call for an end to the controversial bulk data collection of phone records by the NSA, senior administration officials confirm to ABC News. The White House will outline proposed legislation this week that would bring sweeping changes to the National Security Agency's controversial data collection program, ABC's JEFF ZELENY reports. A senior administration official describes the proposal to ABC News as "a sound approach to ensuring the government no longer collects or holds this data, but still ensures that the government has access to the information it needs to meet the national security needs his team has identified." Two officials confirmed to ABC News the plan, which was reported earlier tonight by the New York Times. It calls for phone companies to keep phone records, rather than having the data kept by the NSA. The government could obtain the data only under a judge's order. Senior Congressional officials say this is part of a legislative proposal that will be outlined as soon as today, before the court order that created the current program expires on Friday. This requires Congressional approval. The current program will be renewed, an official said, until this legislation is passed. http://abcn.ws/1gw0rMN

RUSSIA SHRUGS OFF G-7 SNUB AND ADDS TROOPS NEAR UKRAINE BORDER. As President Obama convened an emergency meeting of the G-7 leaders yesterday to turn up the heat on Moscow, the Russian military added to their forces on Ukraine's border. U.S. officials tell ABC News that Russia has sent an additional 10,000 troops to the Ukraine border in the past week, bringing the Russian force there to almost 30,000, according to ABC's MARY BRUCE, JONATHAN KARL and LUIS MARTINEZ. While Russia claims the troops movements are part of military exercises, White House Deputy National Security Adviser Ben Rhodes told reporters, "There's every reason to be skeptical of Russian assertions." Seeking to mobilize the international community to further isolate Russia, Obama met with the G-7 leaders to strategize a response to Russia's takeover of Ukraine's Crimean peninsula. The hastily arranged meeting, on the sidelines of the Nuclear Security Summit, was intended to foreshadow the sanctions Russia will face if it continues down this path, Rhodes said. The leaders were also expected to discuss Russia's future as a member of the G-8, although Rhodes said the U.S. was not prepared to formally kick Russia out just yet. "The door is open to Russia to deescalate the situation," he said. http://abcn.ws/1dmeYu4

-IF A PICTURE SAYS A THOUSAND WORDS, then the message from an image of members of the G-7 meeting together is directed squarely at President Vladimir Putin: no Russians allowed, ABC's ALI WEINBERG notes. With their national flags prominently on display, the remaining members of the G-7 group of industrialized countries (plus two delegates from the EU) met yesterday on the sidelines of the Nuclear Security Summit in The Hague, the Netherlands, to discuss ways to further punish Russia for its takeover of the Ukrainian region of Crimea. PHOTO: http://abcn.ws/1kYzJMo

RUBIO WANTS GOVERNMENT TO CLEAR THE ROAD FOR UBER. What do Sen. Marco Rubio and actor Ashton Kutcher have in common? The Florida Republican and "That '70s Show" star both want to eliminate regulations that prohibit the popular car service Uber Inc. from operating in Miami. In a speech at the new Uber offices in Washington Monday, Rubio, who ordered an Uber car to drive him to the event, made the case for eliminating regulations that he argues stifle innovation, according to ABC's ARLETTE SAENZ. "Regulations should always be used as a way to help the public and ensure safety. It should never be used as a tool of anti-competitive activity," Rubio said. "We should never allow government power and government regulations to be used to protect an established incumbent industry at the expense of an innovative competitor." Miami lawmakers blocked legislation earlier this year that would have allowed San Francisco-based Uber, which operates in more than 70 cities, and similar tech companies to operate within Miami-Dade County. Actor Ashton Kutcher, who is an investor in Uber, criticized Miami lawmakers last month for not allowing the car-sharing service to exist in its county, calling it "Mafioso." http://abcn.ws/1dIuxqE

-ANALYSIS - ABC's RICK KLEIN: If you're a Republican navigating a path to reach milennials, you can do worse than to call an Uber. That's what made Sen. Marco Rubio's speech Monday, outlining how government regulations hold back new business ventures, worth paying attention to. Rubio's crisp explanation of the frustrating and inexplicable regulations that hold back new consumer and commercial products amounts to a fresh argument in favor of conservatism - a type of politics that at least sounds new to a generation that doesn't like listening to politicians all that much. When Rubio explained the situation to Florida college students recently, "Suddenly, I had a bunch of 20, 21 year old anti-regulatory activists on my hands," Rubio said, per ABC's Arlette Saenz. Rubio's recent tendency of bouncing between topics, foreign and domestic, may be keeping the Ubers of the world in business. But on this issue, he may have found something that connects his generational potential to the GOP's very real need to reach new crops of voters. There's no app for that.

LATEST HILLARY CLINTON-JEB BUSH MEETING ADDS TO 2016 CHATTER. No two people spur more breathless presidential speculation than Hillary Clinton and Jeb Bush. So, naturally, when the Republican former Florida governor and former secretary of state took the stage at a higher education conference in Dallas yesterday, albeit a few hours apart, the level of speculation shifted into overdrive, ABC's ABBY PHILLIP notes. But they never appeared on stage together, shook hands for the cameras to see or placated the crowd with lighthearted joking about the potential for a 2016 match-up. Instead, the two possible future presidential candidates focused on the challenge of expanding access to higher education at home and abroad. Clinton was received by rousing applause when she took the stage after a highlight reel of her advocacy on education in Arkansas, as first lady, and as secretary of state, and after a glowing introduction by co-host and former North Carolina Gov. Jim Hunt. And only briefly did she tantalize the crowd by thanking Bush, the event's co-host, for his dedication to education during his time as Florida governor. "I want to thank Jeb Bush, someone else who really focused on education during his time as governor," Clinton said. "And who has continued hat work with passion and dedication in the years since." And with that, the moment passed. http://abcn.ws/1jnCABa

ANTHONY WEINER GETS A NEW JOB. Failed New York City mayoral candidate and disgraced former Congressman Anthony Weiner has a new gig: He's going to be writing his own column. The website Business Insider has hired Weiner, whose well-documented sexting exploits led to his political downfall, to write a monthly political column called "Weiner!" The first installment will be posted Friday. "It will feature Weiner's thoughts on the top political issues of the day imbued with his unique insider's perspective," according to Business Insider. Weiner, who resigned from Congress in 2011 and came up short in New York's mayoral primary last year, said he was looking forward to "the opportunity to add to the always smart and often iconoclastic coverage of politics and policy at Business Insider." http://abcn.ws/1ivfZiv

WHAT WE'RE WATCHING

REID VS. KOCHS: AMERICANS FOR PROSPERITY NOT SURPRISED BY REID'S 'SLASH AND BURN' ATTACKS. If you live in a battleground state this midterm election, you may be wondering who's behind those controversial ads where people share their concerns with the nation's new health care law. But if Senate Majority Leader Harry Reid gets his way, the public will soon know what Americans for Prosperity is, and who its billionaire backers, the Koch brothers are, too. "I'm not surprised that he's doing it," Americans for Prosperity President Tim Phillips told "The Fine Print's" JEFF ZELENY of Reid's recent attacks against the conservative group's chairman David Koch and his brother Charles. "I'm not surprised that he's doing it If you look at his history, his background as really a political slash and burn sort of politician, but this is a calculated strategy." Americans for Prosperity, thanks in part to the financial support of the Koch brothers, is playing a supportive role to Republicans in their fight to win control of the Senate in 2014 with significant ad buys in states with competitive races. The group's ads, which make the case that the president's health care law is failing, target vulnerable Senate Democrats in toss-up races across the country. http://yhoo.it/1nWMbB0

IN THE NOTE'S INBOX

AMERICAN BRIDGE WADES INTO SUPREME COURT FIGHT. In advance of today's Supreme Court oral arguments, a new report from Bridge Project, the c(4) off-shoot of the Democratic super PAC, American Bridge 21st Century, lays out what Bridge's Eddie Vale calls "the facts behind the extreme conservative agenda fighting against birth control and women's access to health care. The plaintiffs are challenging commonsense public policy and Americans deserve to know the truth behind their motives. It is clear that politicians like Senators Rand Paul, Ted Cruz and Marco Rubio, as well as the Susan B. Anthony List, are focused on imposing their own beliefs, with no regard for women's health or right to control their own bodies," said Vale, Vice President of Bridge Project. http://bit.ly/1dmrZDX

WHAT WE'RE READING

"AFP AIRS NEW ANTI-OBAMACARE AD IN MICHIGAN," by the Wall Street Journal's Beth Reinhard. "Another day, another ad blasting Obamacare from the conservative Americans for Prosperity. The latest television spot in the group's $30 million media blitz is airing in Michigan, where the U.S. Senate race pits the former secretary of state, Republican Terri Lynn Land, against Democratic Rep. Gary Peters. Like other AFP ads, the spot features a personal horror story about the health care law, but it also includes a more pointed attack that the health care law, known as the Affordable Care Act, is 'destroying the middle class.' Shannon Wendt of Grand Rapids, a mother of five children, says the law forced her insurer to cancel the family's health care plan, and the replacement 'is not affordable at all.' She adds, 'It feels like a kick in the gut…Congressman Peters' vote for Obamacare is a vote that's destroying the middle class.'" http://on.wsj.com/1hVRQjm

WHO'S TWEETING?

@CRNC: READ: Why Obama is losing millennials http://www.cnn.com/2014/03/24/opinion/zelizer-youth-obama/index.html?sr=sharebar_twitter … #CRNC

@amychozick: And early on Clintons hosted receptions in Chappaqua and DC to introduce Brock to donors to start Media Matters http://nyti.ms/NNeBMU

@BreitbartVideo: Cantor Responds to Breitbart News Report - Says He Is in Support of Boehner as Speaker: http://bit.ly/1hiFDn6 @BreitbartVideo

@PhilipRucker: "He doesn't want a crazy extremist," Adelson friend says of 2016. Sheldon's "neutral" but eyeing Christie, Jeb http://www.washingtonpost.com/politics/billionaire-mogul-sheldon-adelson-looks-for-mainstream-republican-who-can-win-in-2016/2014/03/25/e2f47bb0-b3c2-11e3-8cb6-284052554d74_story.html …

@SantinaLeuci: Robin Roberts to Guest Judge 'Dancing With The Stars' http://abcn.ws/1eJr4Mm