A round-up of this morning's must-read stories.

OPTIONS DWINDLING FOR CLINTON
(Adam Nagourney, New York Times)
In this case, a split was not a draw... In short, Mrs. Clinton could not have asked for a better second chance to turn this campaign around and to make her central case to superdelegates: that Mr. Obama was a damaged general election candidate who would get swallowed up by the Republican Party. Yet she was unable on Tuesday to build her base of support substantially beyond the white, working-class voters who had sustained her for the last month. That will not be lost on the superdelegates, the elected Democrats and party leaders who will ultimately decide this fight. And the superdelegates are where the fight is moving: after 50 nominating contests, there are only 6 left, with just 217 pledged delegates left to be elected, not enough to get either of them over the 2,025 threshold necessary to win the nomination. Mr. Obama’s aides said Mrs. Clinton would have to win close to 70 percent of the remaining pledged delegates and superdelegates to win the nomination, a shift in the campaign’s trajectory that would seem possible only if some big development came along to hurt Mr. Obama.

MORE: Clinton Fails to Get Needed Game-Changer (Beth Fouhy, AP)
Her aides insist she will press anew for a resolution to the disputed contests in Michigan and Florida, both of which she won, but whose results were voided because the primaries were moved in violation of Democratic Party rules. Anticipating those efforts, Obama campaign manager David Plouffe sent a memo to superdelegates reminding them of the math. He said Clinton would need to win 68 percent of the remaining delegates to win the nomination -- an extremely unlikely scenario, made harder by her poor performance Tuesday. "With the Clinton path to the nomination getting even narrower, we expect new and wildly creative scenarios to emerge in the coming days. While those scenarios may be entertaining, the are not legitimate and will not be considered legitimate by this campaign or millions of supporters, volunteers and donors."

OBAMA TAKES DECISIVE STEP TOWARD NOMINATION
(Ben Smith, Politico) 
Sen. Barack Obama took a large and potentially decisive step toward the Democratic nomination Tuesday night, making dramatic symbolic and numerical gains in North Carolina and Indiana. Obama’s emphatic North Carolina victory, and a narrow loss in Indiana, extended his lead in the count of delegates to the Democratic National Convention, and in most counts of the combined popular vote. As important, they diminished Clinton’s rationale for urging Democratic superdelegates to override his delegate lead and give the nomination to her. Her case to party elders — that Obama was a flawed, flagging candidate — lost much of its altitude despite a nail-biting and narrow victory in Indiana. Her bread-and-butter pitch to voters fell prey to the doubts Obama’s television campaign raised about her sincerity. What had been, in the best of scenarios an up hill climb, became far steeper. 

MORE: What Happened in Indiana and N.C. (David Paul Kuhn, Politico)
There were unique findings in the two states that separated these voters from past contests — particularly the power of the issue of economic anxiety. Nearly seven in 10 Indiana voters said the economy was the most important issue, as did six in 10 North Carolinians. That degree of economic concern in Indiana was above financial angst in Pennsylvania or even Ohio, a state hit especially hard by unemployment. But unlike in Pennsylvania, the voters most anxious about the economy were not handily carried by Clinton. In Indiana, she won only a slim majority of these voters and in North Carolina, Obama won a majority. Also on the economic front, it appears Clinton’s gas tax proposal, which was heavily debated this past week, likely did not move votes to her side.

CLINTON AIDES DOUBTFUL ABOUT FUTURE
(Perry Bacon, Jr. and Anne E. Kornblut, Washington Post)
The outcome caused the candidate and her campaign to intensify their efforts to persuade party leaders to include the results of disqualified contests in Michigan and Florida, both of which she won. The Democratic National Committee's Rules and Bylaws committee is scheduled to meet on May 31 to consider two challenges pending on whether, and how, to seat delegates from those states. "Absent some sort of miracle on May 31st, it's going to be tough for us," said a senior Clinton official who spoke on the condition of anonymity in order to be frank. "We lost this thing in February. We're doing everything we can now . . . but it's just an uphill battle."

HOW DOES CLINTON LOSE?
(Marc Ambinder, The Atlantic)
MAY 20 -- THAT'S the date when the campaign unofficially expects to "clinch" the nomination -- when they'll officially have a majority of pledged delegates, which triggers, in their view, the standard for superdelegate decision-making set by party leaders like Nancy Pelosi. I expect -- and the Obama campaign expects -- to see the pace of his superdelegate pick-ups increase. They expect a few superdelegate defections from Clinton as well. Within the next few weeks, Obama might well pass Clinton in the number of superdelegate endorsements. Remember, though: the superdelegates are followers. They're politically wimpy... and they like to be wooed. EXPECT OBAMA in the next few days to prize unity above all else -- and to turn his attention away from Clinton and towards the notion of a unified Democratic Party and the race against McCain. The Clinton campaign will limp to West Virginia with just enough energy and barely any money. The campaign will point to the DNC rules committee meeting on 5/31, but DNC officials tell me that the staff recommendation provided to the committee -- a recommendation that has so far been kept secret -- is not unambiguously favorable to Clinton's interpretation of the rules.

'YES WE CAN' VS. 'NO WE CAN'T'
(Jonathan Cohn, New Republic)
If Obama's slogan is "yes we can," McCain's is "no we can't." Obama wants to invest heavily in better schools and public infrastructure? McCain says it will cost too much money. Obama wants to make sure every American has health insurance? McCain says it's socialized medicine. Obama wants to make free trade more humane? McCain's says no, no, no--that's messing with the free market. Even Obama's calls to change political discourse for the better--the most familiar and, at times, most empty part of his pitch--play into this dynamic. When Obama says he wants to end the politics of division, McCain dismisses it as just a slogan. Whether you think Obama is right or wrong about these ideas--and, yes, I mostly think he's right--he's setting up the fall as a debate between ambition and timidty, between hope and cynicism, between optimism and pessimism.  The last two presidential elections that framed the choice this starkly were in 1992, when Bill Clinton beat George H.W. Bush, and in 1980, when Ronald Reagan beat Jimmy Carter. For all of their ideological divisions, the two shared a fundamentally positive vision: Clinton believed in a "place called hope"; Reagan believed it was "morning in America." Those phrases sound a lot more like Obama's rhetoric than McCain's. And while it's just one factor in the general election, it helps explain why, for the first time in a while, I too am becoming more optimistic--about Democratic prospects for November.

IT'S ALL OVER NOW, BABY BLUE
(John Judis, New Republic)
he Democratic primary is over. Hillary Clinton might still run in West Virginia and Kentucky, which she'll win handily, but by failing to win Indiana decisively and by losing North Carolina decisively, she lost the argument for her own candidacy. She can't surpass Barack Obama's delegate or popular vote count. The question is no longer who will be the Democratic nominee, but whether Obama can defeat Republican John McCain in November. And the answer to that is still unclear. During the last two months, Obama has faltered as a candidate. He has seen his political base narrow rather than widen, and some of his strengths turn into weaknesses. Of course, he has had to deal with the scandal surrounding Reverend Jeremiah Wright, but even so, he needs to remedy certain flaws in his political approach if he wants to defeat McCain in the fall.

THE NOMINEES EMERGE, HOBBLED
(David Brooks, New York Times)
Obama has a much more liberal profile than he did several weeks ago. Moderate, independent voters are now less sure that Obama shares their values. Hillary Clinton voters are much, much more hostile toward him. His supporters look more and more like the McGovern-Dukakis constituency, and the walls between that constituency and the rest of the country are higher than they were weeks ago. Obama is going to have to work hard to tear down those walls over the coming months. He is going to have to work hard first to win over the Clinton voters, who are more economically populist and socially conservative than his supporters. He is also going to have to work hard to win over suburban independents, who are less economically populist than his current supporters. He’s going to have to break conspicuously with orthodox liberalism to re-establish that values connection with people in Ohio and Missouri.

CLINTON DESPERATE FOR A SUPER TURNAROUND
(Roger Simon, Politico)
There is a lot at stake for her that goes beyond the Democratic convention. First, if she doesn’t get the nomination this time, she has to exit in such a way as to not damage her political future. If Obama loses the general election this year, he is unlikely to get a second chance in 2012. (The Democrats don’t like to renominate losers; the last time they did it was with Adlai Stevenson in 1956, and he lost again.) Clinton could try for the nomination again, but even if she does not run for president in 2012, she is up for reelection to the Senate that year. Or she could run for governor of New York in 2010. Or she might want to become majority leader of the Senate. She has options, but only if she manages her endgame carefully. If she becomes known as the candidate who was willing to destroy her party in order to gain the nomination, she is likely to lose not just the nomination but also her political future.