When Sen. Barack Obama slipped into Sen. Robert Byrd's Capitol office one day last year, he was seeking counsel from an elder who had been in the Senate since before Obama was born.

Senators these days, Byrd cautioned the young Illinois Democrat, become fixated on the White House.

"I remember the advice," Obama said matter-of-factly in an interview with The Associated Press last week. "The importance of senators staying in the Senate."

Obama has been in the Senate less than two years. Now he is thinking of running for president. Presumptuous?

"In a country of 300 million people," he said with a laugh, "there is a certain degree of audacity required for anybody to say, `I'm the best person to lead this country.'"

He is not saying that yet. But plenty of people want him to, and he probably will make up his mind in the next few weeks.

It is hard to fathom Obama's meteoric rise in politics.

Three years ago he was little-known, a black state senator with an interesting family history and impressive academic credentials. Now polls show him as the top alternative to New York Sen. Hillary Rodham Clinton in the early chase for the Democratic presidential nomination. No matter that neither senator has announced an intention to run.

Two years ago, Obama gave the keynote address at the Democratic National Convention. Since then, he has:

_taken a high-profile trip to Africa.

_campaigned vigorously for congressional candidates.

_published a second, best-selling book.

_acknowledged that he is considering running for the White House.

On Monday, Obama plans a speech on Iraq at the Council of Foreign Relations, a requisite stop for prominent politicians seeking to showcase their foreign policy chops. Clinton spoke to the group last month.

Both she and Obama have embraced a phased withdrawal of U.S. troops that is tied to specific benchmarks rather than a time.

"I don't know how you change the course without sending a strong signal to the Iraqi government that we are not going to maintain a permanent presence in the midst of civil war," he said in the interview.

Obama, 45, clearly benefits from his rapid rise. He is not burdened by a lengthy Senate voting record. This year's election made him a prize campaign draw, exposing him to crowds across the country and earning useful chits from candidates in states key to the presidential hunt.

Sen. Richard Durbin the senior senator from Illinois and the No. 2 Senate Democrat, urged Obama to hit the hustings in Iowa, home to the first presidential caucuses. As a result of those visits, Durbin said, "I think more people in Iowa are interested in his thought process about the future."

Obama is consulting with some experienced political strategists. Among them are Chicago-based David Axelrod, a senior adviser to John Edwards' 2004 presidential campaign; David Plouffe, a former aide to House Democratic leader Richard Gephardt, and Steve Hildebrand, who ran Vice President Al Gore's campaign in Iowa in 2000.

Other potential Democratic candidates, however, are further along.

Clinton has millions left from her easy re-election campaign this year. Sen. John Kerry of Massachusetts also has millions in hand from his 2004 presidential race. Iowa Gov. Tom Vilsack already has set up his campaign committee.

Political operatives and fundraisers predict that a candidate who wants to be credible as a presidential hopeful must have at least $20 million in the bank by June. Obama is a proven fundraiser, amassing nearly $15 million in his 2004 Senate race and more than $4 million for his political action committee.

"If he decides to run ... he can put the money together and he can attract the talent," Axelrod said.

Barack Hussein Obama Jr. is the son of a Kenyan father and a white mother. He offers himself as a cross-generational politician who wants to move beyond the fallout from the 1960s and break the conventional left and right, liberal-conservative pigeonholes of American politics.

"Both the '60s revolution and the subsequent backlash ended up locking us into an either or debate on almost every issues," he said. "Either you were pro-military or anti-military. You were pro-traditional family or somehow you were against traditional family. The American people living their lives have a much more complex view of these issues."

Obama is from a new generation of black politicians.

He is not a product of the civil rights movement like Jesse Jackson. But his identity as a black man is prominent. A photograph of Martin Luther King Jr., a portrait of Supreme Court Justice Thurgood Marshall and images from the civil rights era hang from his office walls.

The most conspicuous item in his office is a set of red boxing gloves autographed by Muhammad Ali, set against a photo backdrop of Ali taunting a fallen Sonny Liston during their 1965 rematch.

The office mementos serve as Obama's personal touchstone to an era of profound change.

"The '60s," he acknowledged, "were a transformative period in this country."

The Nov. 7 elections that shifted control of Congress to the Democrats also helped Obama expand his areas of expertise in decidedly presidential directions. Already a member of the Senate Foreign Relations and Veterans' Affairs committees, Obama asked for and received seats on the Homeland Security and Governmental Affairs and the Health, Education, Labor and Pension committees.

Sen. Richard Lugar (news, bio, voting record), an Indiana Republican and current chairman of the Foreign Relations Committee, has become something of a mentor to Obama. The senators have traveled to the former Soviet Union together and sponsored legislation on nonproliferation of conventional weapons and on fuel economy.

Lugar also has a special insight, having run for president himself in 1996 while still in the Senate.

"I found in my own experience, if you want to do one well, you probably better decide which one," Lugar said.

In his book, "The Audacity of Hope," Obama displays a candid self-awareness about the reality and limits of his political appeal. "I am new enough on the national political scene that I serve as a blank screen on which people of vastly different political stripes project their own views," he wrote.

Or as Democratic policy strategist Will Marshall of the centrist Progressive Policy Institute put it: "Voters want to know what lodestars presidential candidates steer by. That's something that a relative newcomer like Senator Obama has not had a chance to convey yet."

His fame creates its own pressures.

"He ought to try it," said Ronald Walters, a political scientist at the University of Maryland who served as a senior consultant to Jackson's presidential campaigns. "He's not going to be able to snatch back his rise in the polls and his stature in the public. This is a very special moment for him."

But fame also attracts scrutiny.

This month, a Chicago Tribune report said the wife of a developer and political fundraiser now under indictment purchased a lot last year next door to Obama's new house. Obama then paid the developer, Antoin "Tony" Rezko, $104,500 to expand Obama's yard into part of the lot.

Rezko had donated to Obama's campaign and had held a fundraiser for him. He has pleaded not guilty to charges that he participated in an unrelated kickback scheme involving investment firms seeking state business.

"Purchasing a piece of property from somebody who has been a supporter of yours I think is a bad idea," Obama told the AP. "It's an example where every once in a while you're going to make a mistake and hopefully you learn from it."