CHICAGO — Democratic State Sen. Barack Obama trounced Republican candidate Alan Keyes in the contest to become the United States’ only black senator.

Obama defeated the conservative Maryland talk-show host with about three-fourths of the vote in a race that had long been expected to swing in his favor.

“I don’t know about you, but I’m still fired up,” Obama said as he stepped on the stage at his victory party. His speech focused on renewal of hope and trust in government, which he hopes to create.

During his speech, Obama was careful to note that he does not assume his landslide victory means support across the state.

“I’m not going to be under the illusion that all of the people of Illinois agree with me on every one of my policies,” Obama said at the Hyatt Regency Hotel, where his campaign party was held. “We will not be measured by the margin of our victory, but whether we can provide concrete improvements to the lives of the people in this state.”

Obama’s wife, Michelle, said that his victory was unexpected when he began the race.

“No one could have predicted that the senator from Illinois would be a skinny guy with no money, no organization and a funny name,” she said in her introduction of her husband.

After Obama announced his candidacy, he became a star of the Democratic Party, delivering one of the keynote addresses at July’s Democratic National Convention in Boston.

He also become popular with many Northwestern students who have followed his campaign and started their own chapter of Students for Obama.

Leah Edelman, who attended the election night party, first met Obama in a Mexican Heritage march and was impressed with his personality.

“He shook my hand and said hello, and I was very drawn to him,” said Edelman, a McCormick senior.

Obama, a moderate on most issues, enjoyed the backing of many voters in the Republican Party who found Keyes’ views too conservative.

Obama favors abortion rights and supports broadened health care in Illinois and stricter gun control.

Keyes conceded the election at a campaign party attended by about 200 supporters at the Chicago Hilton and Towers. Keyes has said he will remain in Illinois after the race and pledged Tuesday to root out corruption and clean up the state’s Republican Party.

Keyes told supporters that he stood by his principles throughout his campaign, acknowledging that the fight was a “long, hard slog.”

“Barack Obama said he was going to give me a spanking,” Keyes told a laughing crowd. “Why do you laugh? I think it was quite true.”

But Keyes, in one of many biblical references, said Jesus suffered as well, but did not relent.

“He was spanked as well,” he said. “I think they called it a scourging.”

Keyes entered the race in Illinois at the last minute after sexual allegations surfaced in the divorce papers of former Senate candidate Jack Ryan, causing Ryan to drop out. Polls throughout Keyes’ campaign placed him far behind Obama.

Keyes’ latest defeat adds to two failed runs for the Republican presidential nomination and two failed runs for senator in Maryland. He leveled blame in his speech on Illinois Republicans who were cool toward his candidacy and on the media, which he said failed to treat his campaign with the same warmth as Obama’s.

Keyes ran a campaign platform on conservative social positions, in which right-wing views on abortion, gay marriage and gun control were the hallmarks of his campaign. His speeches often were studded with scripture, and Tuesday was no different, as he spoke with ministerial flair.

Keyes volunteer David Lobl, a second-year student in the School of Continuing Studies, said he supported Keyes’ candidacy because of his integrity and his commitment to principles.

“He’ll say what’s on his mind,” Lobl said.

Reach Zach Fridell at [email protected] and Dan Strumpf at [email protected].