(4:29 p.m. ET)  

John McCain said Friday that he worries terrorists will try to tilt the election against him in November.

McCain was asked by an audience member during a town hall meeting in Springfield, Pa., if he thought Al Qaeda in Iraq or another terrorist group would "ratchet up" attacks to increase U.S. casualties right before the election, to encourage voters to elect a president "more willing to withdraw."

"Yes, I worry about it," McCain answered. "I know that they pay attention because (of) the intercepts that we have of their communications."

McCain, who is embarking on his eighth trip to Iraq this weekend, vigorously defended his effort to stop Democrats from imposing a troop withdrawal deadline there during an interview with FOX News Thursday.

He stressed that "this war will be won if we stay with it," but addressed the challenges Friday.

"The hardest thing to counter in warfare is someone or a group of individuals who are willing to take their own lives in order to take others," he continued. "But I also believe that they may be able to carry out some spectacular suicide attacks, but we do have them on the run."

-- FOX News' Cristina Corbin contributed to this report.

McCain Passes Up Charter Flight, Takes Amtrak

(3:15 p.m. ET)

John McCain traveled like a man of the people Friday morning, riding an Amtrak train to Philadelphia after a late night of voting in Washington.

"Nice to see you, nice to see you," McCain said to workers and passengers who greeted him on the 8 a.m. high-speed Acela Express train.

McCain, accompanied by a campaign aide, was left alone by the public as he sat in the first-class car for much of the 1 1/2 hour trip.

He drank coffee and read several newspapers -- The Washington Post, The New York Times, Wall Street Journal and USA Today. And he talked on his cell phone with a campaign adviser for several minutes.

The night before, the Arizona senator had flown from Philadelphia to the nation's capital for votes on the federal budget.

As Republican presidential nominee-in-waiting, McCain had a campaign charter plane at his disposal.

But he took a commercial flight so that he could fly into Washington Reagan National Airport, nearer the Capitol, and he returned to Philadelphia by train.

-- The Associated Press

Obama Camp Says Clinton Outlook 'Divorced From Reality'

(12:38 p.m. ET)

Barack Obama's campaign accused Hillary Clinton's team of ignoring reality in their claim Thursday that he can't win the general election without winning big states like Pennsylvania.

"It can't inspire too much confidence in the Clinton campaign when their pollster ignores both polls and math by making comments as divorced from reality as this one," the campaign said in a statement late Thursday night. "Senator Obama is leading in delegates, states won, the popular vote, and fares better than Senator Clinton against John McCain in poll after poll, including critical swing states like Iowa, Colorado, Pennsylvania, New Mexico and Wisconsin."

Obama has taken heat for apparently downplaying the April 22 Pennsylvania primary, which comes with 158 delegates and is the biggest prize remaining on the primary calendar. Polling shows Clinton ahead in the Keystone State, and while Obama pledged to campaign vigorously there he's spreading his time out in other upcoming contest states like Indiana and North Carolina.

Clinton strategist Mark Penn made the case on a conference call Thursday that if the Illinois senator doesn't come through in the bigger states, "Obama really can't win the general election."

The Clinton campaign argued that Pennsylvania is diverse territory, representative of a broad cross-section of industries, and has been historically critical to presidential candidates.

Obama campaign manager David Plouffe said recently that Clinton will probably win Pennsylvania by a "healthy margin."