A new survey conducted Saturday by Ogden & Fry shows Chicago Mayor Rahm Emanuel polling at 48.5 percent, compared to challenger Jesus 'Chuy' Garcia's 32.1 percent.
About 18 percent of the 951 survey respondents were undecided in the poll, which has a margin of error of plus or minus 3.24 percent.
Previous Ogden & Fry polling conducted March 14 showed Emanuel at 47.1 percent and Garcia at 37.6 percent, with 16 percent of survey respondents undecided.
The polling firm's memo issued Sunday says, "Emanuel's heavily criticized attack ads continue to have an impact on the race."
"Emanuel's use of money is a good example of why the politician with the most money frequently wins," the memo reads, adding that "turnout and the under-polling Hispanic vote are two factors to still consider also."
On Friday, Ogden & Fry conducted a mayoral poll without the "undecided" option, in which 55.8 percent of the 877 survey respondents opted for Emanuel, while 44.2 percent picked Garcia. That poll has a margin of error of plus or minus 3.38 percent.
Chicago's mayoral runoff contest is April 7.