On this day in 1974 Hank Aaron hit his 715th home run, breaking Babe Ruth's record. On to today's top stories:

"Shift at Top May Mean Shift in Tone for Clinton" (John Harwood and Jeff Zeleny, New York Times) With the demotion of Mark Penn the Clinton campaign has went through its second major reorganization this year, the first being some weeks ago with the demotion of Patti Solis Doyle.

"McCain Stands Firm on Iraq" (Johanna Neuman, Los Angeles Times) Kicking off a week of Iraq focus on Capitol Hill, John McCain gave a speech to the VFW in Kansas City where he reiterated the grave consequences of failure.

"Iraq Hearings on Capitol Hill Could Put McCain in Spotlight" (David Jackson, USA Today) In many ways John McCain owes his political survival to Gen. David Petraeus. Things are different of course this time around with McCain now the nominee, but the commander's testimony to Congress is no less important for McCain's fortunes.

"Superdelegates Give Themselves Wiggle Room on Clinton-Obama" (Mike Soraghan, The Hill) Reporter Soraghan's lede is good: "As the fight over superdelegates gets harder, some of the superdelegate endorsements are getting softer."

"McCain Raises $15 Million in March" (Jim Kuhnhenn, Associated Press) They aren't Obama-Clinton numbers, but McCain's March haul is his largest single-month amount so far. The question is whether McCain can keep the momentum going.

"Clinton: Bush Should Not Open Olympics" (Devlin Barrett, Associated Press) Clinton didn't call for a complete boycott of the Olympics just the opening ceremony. President Bush has maintained that the Olympics are a sporting event, not a political event.

"Obama Gets Help in Pennsylvania" (New York Times) One factor helping Obama keep pace with Clinton in the Keystone State is his money advantage. The SEIU, in particular, is pumping almost $1 million into the state in door-to-door canvassing.

"Bill Clinton Visits Puerto Rico, Rich in Culture and Delegates" (Eli Saslow, Washington Post) Bill Clinton campaigning in Puerto Rico -- just another sign of this crazy election year.

"Clinton's Tale Part Truth, Part Errors" (Associated Press) The latest story to blow up in Clinton's face is the one she used to tell about a pregnant woman without health insurance who ends up losing her baby and dies. The hospital in question disputed the accuracy of the tale and said the woman was never refused treatment and in fact had health insurance.

Get today's other election stories at RCP's Politics and Election page.