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...