Nearly 20,000 people gathered at Hyde Park of Chicago on Saturday night to hear Obama trying to energize voters ahead of Tuesday's mid-term elections in order to bolster the Democratic base.

The top Democrat urged his Chicagoan supporters in his speech to grasp the chance to "set the direction of this state and this country for years to come" by going out to vote. He also warned them his agenda depends on the party' s ability to retain control of Congress, otherwise, all the progress of his first two years in office will face reversal.

Despite the fact that Obama enjoys great popularity here, poll showed that Pat Quinn, Senate nominee Alexi Giannoulias and three Democratic congressmen are at risk of losing their seats next Tuesday, according to Chicago Sun-Times.

The goal of Obama's visit is trying to fend off the challenge from Republicans for the president's old U.S. Senate seat as well as the office of Illinois governor.

It is Obama' s first public appearance in Chicago since his election-night victory event in Grant Park, Chicago two years ago, and the third stop in a day of his campaigning trail after Connecticut and Pennsylvania.