A round-up of this morning's must-read stories. For family reasons, I won't be posting for the rest of the day. But check back later for an item or two from NEWSWEEK's political team. And thanks, as always, for reading.

CLINTON'S CHIEF STRATEGIST STEPS DOWN
(Washington Post)
Penn had been a polarizing figure within the Clinton campaign for months because of his personality as well as his strategic vision, but his departure came as a result of another continuing controversy -- the conflicts of interest that resulted from his representing major clients as president of Burson-Marsteller, the giant public relations firm, while working for Clinton. 

IN SUPERDELEGATE COUNT, TOUGH MATH FOR CLINTON
(New York Times) 
Her aides have lobbied to persuade those still uncommitted superdelegates to back her — or to continue holding out so her campaign has the chance to demonstrate momentum and superior electability in primaries from Pennsylvania’s on April 22 through Montana’s on June 3. Yet Mrs. Clinton’s once formidable lead among superdelegates who have announced preferences has shrunk to 34 by the Obama campaign count. The pool of remaining uncommitted superdelegates for her to draw from has dwindled to around 330, fewer than half the overall total of 795 superdelegates.

CROSSING PATHS, CANDIDATE FACE THE SAME AUDIENCES (New York Times) 
Because the last few primary states matter much more than anyone could have anticipated when the Democratic presidential race began many months ago, Senators Hillary Rodham Clinton and Barack Obama spent the weekend chasing each other across the vast northern expanses of the Great Plains and the Rockies. 

OBAMA MAY NOT HAVE FULLY CONTAINED DAMAGE FROM EX-PASTOR
(Wall Street Journal)
Recent polls suggest that, in key swing states, the New York senator fares better in head-to-head matchups with Republican nominee Sen. John McCain than does Sen. Obama. In Ohio, Sen. Clinton led Sen. McCain 48% to 39%, while Sen. Obama led Sen. McCain 43% to 42% in Quinnipiac University polls conducted in the last week of March. In Pennsylvania, Sen. Clinton had a 48% to 40% lead against Sen. McCain while Sen. Obama was ahead 43% to 39%. The polls credit Sen. Clinton's advantage to her strength among white voters. No Democrat has won the presidency with a majority of white voters since 1964, and no president from either party has been elected without winning two of the three swing states of Ohio, Pennsylvania and Florida since 1960. In those three states, some 23% of white Democrats would defect to Sen. McCain in a matchup with Sen. Obama, compared with 11% who would abandon Sen. Clinton, according to the Quinnipiac polls.

WITH POLL NUMBERS FOR CLINTON AND OBAMA STATIC, PENNSYLVANIA PRIMARY COULD HINGE ON MOBILIZING VOTERS ON ELECTION DAY
(Philadelphia Inquirer)
The last 16 days before the Pennsylvania primary - more so than in most campaigns - will be more about mobilization than persuasion, more about each camp's maximizing its own base than encroaching on the other's demographic turf. What's seemingly permanent in the race, beyond the tightness, is the makeup of the two rival coalitions - with Obama relying on young people, college graduates, and African Americans and Clinton counting on older people, women, and white working-class voters.

THE NEXT CAMPAIGN STOP: IRAQ HEARINGS
(Washington Post) 
When Army Gen. David H. Petraeus and Ambassador Ryan C. Crocker travel to Capitol Hill tomorrow, they might be the ones before the microphones, but the cameras will be trained on three of their inquisitors: Sens. John McCain, Hillary Rodham Clinton and Barack Obama. 

THE VODKA CHRONICLES
(Maureen Dowd) 
It was quite disheartening Thursday to see a McCain spokeswoman telling The Associated Press, in a story about how Cindy McCain helped her husband’s political career bloom with her multimillion-dollar fortune from the family beer business, that the senator is a virtual teetotaler. “Senator McCain rarely, if ever, drinks alcohol,” Jill Hazelbaker averred. McCain’s pals know him as a man who enjoys libations of vodka with little green cocktail olives. Over the years, at dinners with reporters, I noted he had the habit of ordering one double vodka and sipping it slowly. And there was that famous Hillary-McCain Estonian drink-off in 2004, when Hillary instigated a vodka shot contest and McCain agreed with alacrity (even though he later offered a sketchy denial). Maybe now that he’s the presumptive Republican nominee, his campaign wants to put his vices in a vise and sanitize the wild side of the man whose nicknames in high school were “Punk,” “Nasty” and “McNasty.” ... If his campaign is bowdlerizing, let’s hope it stops before he’s a bland McNice. Americans, after all, don’t trust candidates without any vices.