ST. CHARLES, Ill. — As he heads toward the cattle barns at the Kane County Fair in deep Republican country, Democrat Barack Obama cannot take more than three steps without being swarmed by autograph-seeking fans.
The sunburned farmers and rural residents are mostly from towns too small to warrant boldface on a road map. Munching fried steak on a stick, farmer Darryl Collins strains to hear the U.S. Senate candidate's every word.
"Can you sign my T-shirt?" asks Collins, 19, trying to speak above the rumble of animals and excited voters. "Or maybe my cow?"
Obama, a state senator representing South Chicago, is happy to sign a scrap of paper for Collins, and the farmer is giddy to get a souvenir of what's become an outright odd political situation.
Just a year ago, few people in Obama's own constituency would have recognized this lanky man with the baritone voice. Now, even in a county that supported President Bush by a large margin in 2000, voters are embracing Obama.
And tonight, Obama will deliver the keynote speech at the Democratic National Convention in Boston.
"Everyone in this country is going to know who Barack Obama is," said Sen. Jon Corzine of New Jersey, chairman of the Democratic Senatorial Campaign Committee.
Obama shot to prominence when the Illinois Republican Party imploded in recent months, making him essentially a shoo-in for the Senate. If Obama wins, he'll be the third black senator since Reconstruction.
So who is this 42-year-old son of a Kenyan economist and a Kansas-born anthropologist, who was born in balmy Hawaii and raised in the sprawl of Jakarta?
"Barack is either the smartest politician we've seen in years, or the luckiest," said Paul Green, a political scientist at Roosevelt University in Chicago. "The reality? It's probably a bit of both."
Illinois Republicans find themselves in the awkward spot of being without a candidate to oppose Obama, after Jack Ryan dropped out last month because divorce records alleged he tried to force his wife to visit sex clubs. Two former Illinois governors, two state senators, several wealthy businessmen and former Bears coach Mike Ditka have declined to run against Obama in the race to replace retiring Republican Sen. Peter Fitzgerald.
The Democratic Party has piled on, helping add $4 million to Obama's $10-million war chest in the last three months.
With Republicans narrowly controlling the Senate, an Obama victory would shift the chamber that much closer to a Democratic majority. The Democrats plan to feature him in some of its national advertising to boost black voter turnout this November, particularly in several key Midwestern states.
Party officials point out that Obama has been married to the same woman for more than a decade, committed no felonies and avoided major scandal -- no small accomplishment in Illinois politics.
Obama has been in great demand since getting the key convention assignment: He's appeared on political talk shows, granted dozens of newspaper interviews and been a fixture at political rallies.
As keynote speaker, he'll join an illustrious line of politicians such as former New York Gov. Mario Cuomo and Ann Richards, a former treasurer of Texas who later became governor.
Obama is a bit taken aback by his swift rise. "I haven't changed," he said. "It's the situation that's changed. I'm still just me."
Home for Obama is the wealthy Chicago neighborhood of Hyde Park.
Here, in a four-bedroom apartment, he and his wife, Michelle, are raising two young daughters on a street lined with gnarled trees and aging brownstones in South Chicago. The street is home to gleaming BMWs and minivans from which mothers haul out youth baseball jerseys.
But he is just as at home wandering around the city's poor neighborhoods, where he spent years working with residents to improve conditions in the public housing projects.
Obama's understanding of poverty stems from his youth.
His mother, Ann, was born in a small farm community in Kansas, where the family line traces back to ramshackle homesteads.
His father, also named Barack, was a foreign-exchange student from Kenya whose family lives near Lake Victoria. They too were farmers, working the land and protecting the cattle from wild animals and tribal raids.
A scholarship took Obama Sr. to Honolulu. A desire to explore new worlds and job opportunities brought Ann and her family to the tropical state. The two met and soon married, much to their families' horror.
"My father's family sent letters, saying that he had disgraced the family by marrying a white woman," said Obama, whose parents have since died.
When Obama Sr. headed to Harvard in the mid-1960s -- and later returned to Kenya -- he left behind Ann and a toddler. The couple later divorced. Before Barack was old enough to go to school, his mother had remarried, to an Indonesian oil manager.
They moved to Jakarta in 1964. Obama was barely 4. But his memories of that time, detailed in his 1995 autobiography, "Dreams From My Father," are stark and clear.