A new survey by Lake Research Partners on Chicago's April 7 mayoral runoff election shows challenger Jesus "Chuy" Garcia polling at 35 percent and incumbent Rahm Emanuel "only eking out fifty percent when undecided voters are pushed to make a decision."

That's according to Lake Research Partners' polling memo, sent to the Chicago Teachers Union on Tuesday. 

The national public opinion and political strategy research firm conducted the telephone poll of 600 likely Chicago voters, including an oversample of 100 Latino voters, on March 26 through March 29. The survey has a margin of error of plus or minus 4 percent.

Lake Research Partners maintains that almost one in five likely Chicago voters in the mayoral runoff election is still undecided. According to the polling firm, the Chicago mayoral runoff contest is "still too close to call."

The new polling data shows Emanuel is "continuing to suffer from solidly negative job performance ratings and still struggling to cobble together a solid majority one week out from the election," according to Lake Research Partners.

"In the meantime," the memo adds, "challenger Chuy Garcia is steadily raising his name recognition and positioning himself to pick up a disproportionate share of the undecided voters, who comprise nearly twenty percent of the electorate and who are unambiguously put off by the prospect of a second Emanuel term."

Among the survey respondents who supported Emanuel in the poll, 40 percent considered themselves to be strong supporters of the mayor, and 5 percent defined themselves as "not-so-strong supporters" of Emanuel.

"The remaining 5 percent start out undecided and only default into Rahm's camp when instructed by the interviewers to pick the candidate they would lean toward today -- a scenario that helps the better known incumbent," the polling memo reads.

Lake Research Partners added the following in the polling memo:

While Chuy's substantive name ID is hovering near eighty-percent citywide, that is not the case for undecided voters, fully half of whom still have not formed an opinion of him.

Despite knowing Rahm better than Chuy, these undecided voters look far more accessible to the challenger than the incumbent. A 56% majority of all runoff voters rates the job Rahm is doing as Mayor as "just fair" or "poor", but that number jumps to 67% among undecided voters. Moreover, by a 12-point margin voters citywide see Chuy as the candidate more likely to "work for the people, not special interests", but that margin doubles to a 24-point advantage among undecided voters. Perhaps the data point that most dramatically highlights the potential for Chuy to make disproportionate gains in the final days is Rahm's re-elect number (a measure of an incumbent's strength independent of the challenger) among undecided voters, which sits at just 4%. That leaves 96% who would consider someone else or who would vote to replace Rahm.

With nearly one-in-five voters undecided in the final week of this race, the outcome is still too close to call. Chuy is well-positioned to coalesce undecided voters and soft-Rahm backers, but will need to be competitive on the air and on the ground in order to capitalize on these dynamics.