Washington ? Sen. Barack Obama of Illinois said Sunday that he was considering a run for the Democratic presidential nomination in 2008, backing away from previous pledges to serve out his full six-year Senate term.

Obama, 45, told NBC’s “Meet the Press” that he would not make any decision before the Nov. 7 midterm election.

“I am still at the point where I have not made a decision to – to pursue higher office,” he said, “but it is true that I have thought about it over the last several months.”

As a candidate for the Senate, Obama entered the national spotlight as the keynote speaker at the 2004 Democratic National Convention. He won the Senate seat that November with 70 percent of the vote.

Twice before on “Meet the Press” – soon after that election and again this past January – Obama stated flatly that he would serve his full Senate term.

On Sunday, he attributed his possible change of heart to “the responses that I’ve been getting over the last several months” while campaigning for Democratic candidates across the country.

“He is the most in-demand speaker in the Democratic Party,” said David Axelrod, a Chicago-based media consultant who advised Obama’s Senate campaign. “He gets 300 invitations a week.”

Time magazine recently featured a photo of Obama on its cover with the headline “Why Barack Obama could be the next president.” The senator is promoting his new book, “The Audacity of Hope: Thoughts on Reclaiming the American Dream.”

He told NBC that although the door to a potential candidacy had opened “a bit,” he had not yet thought about a White House bid “with the seriousness and depth that I think is required.”

“My main focus right now is in ’06 and making sure that we retake the Congress,” he said. “After Nov. 7, I’ll sit down and consider – and if, at some point, I change my mind, I will make a public announcement and everybody will be able to go at me.”

Asked about his lack of executive experience – his only previous elective office was state senator in Illinois – Obama said: “Well, I’m not sure anybody is ready to be president before they’re president. You know, ultimately, I trust the judgment of the American people that in any election, they sort it through.”

According to Axelrod, Obama has “concluded that he should at least look at this … It is certainly something that is on his radar screen.”

But he has not taken any steps to hire staff or begin raising money for a national campaign, Axelrod said.

“There is no active campaign going on,” he said.