DENVER - It’s a question that has dogged Republican John McCain since he became the Republican presidential nominee.

Would he run for a second term in office if he wins the White House in November?

The 72-year-old Arizona senator, who would be the oldest person to become president in U.S. history, isn’t saying.

“That’s something that every president doesn’t consider until after the appropriate time,” McCain told Reuters in an interview. He often plays down or jokes about his age on the campaign trail.

Critics charged that his running mate choice of Alaska Gov. Sarah Palin, who has little experience on the national stage, was irresponsible given the Arizona senator’s health history, which includes brushes with cancer.

But Palin’s debate performance on Thursday night reassured some that she would be up to the challenge if McCain could not or would not continue in the Oval Office.

Palin for president in 2012 anyone? 

Read the full Reuters interview story with McCain here.

Click here for more Reuters 2008 campaign coverage. 

- Photo credit: Reuters/Brian Snyder (McCain at a town hall meeting in Denver, Colo.)

DENVER — Democratic vice presidential nominee Joe Biden, 65, admits he’s getting a little touchy about the fact that he’s so much older than running mate Barack Obama , 47.

“If I hear one more time he was 11 years old when I went to the Senate, I’m going to smack somebody,” Biden joked, drawing laughter and applause at a breakfast meeting with convention delegates from Biden’s native state of Pennsylvania.

A smiling Biden, first elected to the Senate 35 years ago, noted there are just four senators in the 100-member chamber with more senority than him.

“But there are still 44 older than me,” Biden said, prompting more laughter.

On a serious note, Biden said he and Obama must capture Pennsylvania on Election Day to take the White House in their battle against Republican John McCain.

“We cannot win without winning Pennsylvania and it is that simple,” said Biden, who was born and raised in Scranton, Penn., and later moved to Delaware where he was elected to the Senate in 1972.

Promising to spend plenty of time campaigning in the state, Biden, affectionately known as “Pennsylvania’s third senator” for the work he has done for it in Congress, Biden said to sustained cheers and applause, “I’m coming home.”

Click here for more Reuters 2008 campaign coverage.