Hillary Rodham Clinton will get it started at 11 a.m. She'll be joined by U.S. Rep. Joe Sestak for a town-hall meeting on Iraq at Radnor High School in Radnor. After that, she'll make a brief trip to North Carolina, which holds its primary on May 6. She'll be back in the state tomorrow.

Bill Clinton has three area events scheduled on his wife's behalf in the late afternoon and evening. The former president is to be at Upper Dublin High School in Fort Washington at 6 p.m., at North Penn High School in Lansdale at 7:15, and at the Crane Arts Center, 1400 North American Street, in Philadelphia at 9.

But the biggest event of the day, in terms of crowd size, will no doubt belong to Barack Obama. His campaign has scheduled an outdoor, public, evening rally at Fifth and Market. Gates open at 6 p.m. Although there's no time set for Obama's actual appearance, it likely will occur at 7:30 or so.

Tomorrow, Obama will be evoking the politics of yesteryear with a whistlestop tour, taking a train along the Amtrak line from Philadelphia to Harrisburg. The tour starts at the Wynnewood train station (he's scheduled to speak at 11:30 a.m) and ends with a rally on the steps of the State Capitol at 8:45 p.m. Intermediate stops are Paoli (2 p.m.), Downingtown (3:45) and Lancaster (6).

Contact senior writer Larry Eichel at 215-854-2415 or leichel@phillynews.com.