Barack Obama spoke to reporters on the plane traveling from Chicago to Washington. (Photo: Alex Brandon/Associated Press)

DULLES, Va. – With a six-week interval between primaries, the Democratic presidential candidates have a little more time on their hands after a chaotic string of week-to-week primaries and caucuses.

It leaves a little more time for telephone calls. To superdelegates.

“The last time I talked to Al Gore was last week,” Senator Barack Obama said today, speaking to reporters as he flew from Chicago to Washington.

That morsel of information was buried near the end of a question-and-answer session. Asked if he would divulge what they talked about, Mr. Obama smiled and simply said, “No.”

It’s been awhile since Mr. Gore’s name has come up in the context of the prolonged Democratic presidential contest. While people close to the former vice president say he has been following the race closely, he has given no signals that he is willing to step into the battle between Mr. Obama and Senator Hillary Rodham Clinton.

And how about John Edwards?

Mr. Obama said he had spoken to him “within the last two weeks.” Asked if he was expecting anything from Mr. Edwards, Mr. Obama replied, “Some good advice.”

(Mr. Edwards is not a superdelegate, of course, but could still influence the race if he decided to endorse one of his former rivals.)

But back to the phone call between Mr. Obama and Mr. Gore. Does it hold greater meaning or was it just a routine course of business?

That question was not resolved as Mr. Obama walked to the front of his plane