A once obscure Democratic state senator from Chicago's South Side emerged Tuesday as the front-runner in next Tuesday's primary for his party's U.S. Senate nomination, according to a new poll.

"It often takes time and money to break into the public consciousness," Barack Obama (search) said Tuesday. "People have been paying more attention."

Obama has been showing a television commercial in which the late U.S. Sen. Paul Simon's (search) daughter, Sheila Simon, says Obama was "cut from that same cloth" as her father.

Obama's closest rival, state Comptroller Dan Hynes (search), said it was down to a two-person race and warned against trusting the polls. He told voters in Peoria that he's the candidate best able to represent the entire state and to bring back jobs to Illinois.

Political consultant Don Rose said Obama, whose father was from Kenya, was late in getting the support of a large majority of black voters, but has now fashioned a strong coalition of Chicago's "lakefront liberals," suburbanites and blacks.

As Obama and Hynes have risen, multimillionaire Blair Hull has plummeted in the polls in the wake of revelations of verbal and physical abuse during a divorce.

"Public opinion sways back and forth," Hull said. "I trust the voters of Illinois to choose who can truly represent them."

The Chicago Tribune/WGN-TV poll of likely Democratic primary voters found 33 percent supported Obama, up from 15 percent in a poll taken three weeks ago. Hynes was second with 19 percent, up from 11 percent, while Hull plunged from 24 percent to 16 percent.

The poll had a margin of error of plus or minus four percentage points.

The poll showed Jack Ryan holding onto a strong lead among the Republican candidates, with support of 32 percent of likely voters. Eleven percent said they would vote for dairy owner James Oberweis, and 10 percent picked suburban Chicago businessman Andy McKenna.