According to authorities, William Helm was involved in a scuffle on the night of the February 22 election in Chicago.
Helm was arrested at 10:25 a.m. in the 4200-block of North Western Avenue, police News Affairs Officer Michael Fitzpatrick said.
The 47th Ward office of Ald. Eugene Schulter is located at 4237 N. Lincoln Avenue, according to an online search. Helm is the president of the ward's Democratic organization, according to various media reports.
The victim told police that Helm allegedly struck him on the left side of the face with a closed fist about midnight on Feb. 23 in a bar in the 4300-block of North Western Avenue. Two other offenders allegedly punched and kicked the victim. Bar patrons broke up the fight and the offenders fled the scene.
The bar, The Celtic Crown Public House, is located at 4301 N. Western Ave., according to an online search.
Helm is scheduled to appear April 20 in court.
(The Sun-Times Media Wire contributed to this report.)