The ruling, which still needs final approval from the Chicago Board of Election Commissioners, is a political win for Emanuel because it could help him silence critics who have persistently argued he isn't a Chicago resident. The board is scheduled to meet later Thursday and will likely make a decision.
"While the decision rests with the Commissioners, I am encouraged by this recommendation . . . Chicago voters should ultimately have the right to decide the election - and to vote for me or against me," Emanuel said in a statement Thursday.
Election board hearing officer Joseph Morris said evidence suggests that Emanuel had no intention of terminating his residency in Chicago, left the city only to work for Obama and often told friends he intended to live in Washington for no more than two years.
"Illinois law expressly protects the residential status and electoral rights of Illinois residents who are called to serve the national government," Morris, a Republican attorney in private practice in Chicago, wrote in his 35-page ruling.
Officials have tried to expedite mayoral ballot challenges before the Feb. 22 vote, but the board's decision is almost sure to be challenged in the courts.
"The hearing officer is sort of like an Italian traffic signal - it's a mere suggestion. He is basically giving his opinion," Paul Green, a political scientist at Roosevelt University in Chicago, said before the ruling was issued.
More than two dozen people challenged Emanuel's candidacy, contending he didn't meet a one-year residency requirement. Emanuel quit his job as Obama's top aide and moved back to Chicago in October after Mayor Richard M. Daley announced he wouldn't seek a seventh term.
Emanuel is part of a crowded field of more than a dozen candidates, including former U.S. Sen. Carol Moseley Braun, U.S. Rep. Danny Davis, former school board president Gery Chico, City Clerk Miguel del Valle and state Sen. James Meeks, the pastor of a South Side mega church.
Since returning to Chicago in October to run for mayor, Emanuel has enjoyed strong name recognition in the race and already has run several television ads. A recent Chicago Tribune/WGN poll showed Emanuel as the only candidate in double digits with more than 30 percent support, although 30 percent remained undecided.
In his recommendation, Morris wrote that the question wasn't whether Emanuel established residency in Illinois in 2010, but whether he abandoned it. Morris said he found no evidence that Emanuel had done so, arguing that "the touchstone of continued residence is the intention of the resident, and not the physical fact of `having a place to sleep."'
Morris also noted that Emanuel was born and married in Chicago, owns a home in the city where he still keeps valuable possessions, has an Illinois driver's license and voted in Chicago in every election between 1999 and February 2010.
"The preponderance of this evidence establishes that the candidate never formed an intention to terminate his residence in Chicago; never formed an intention to establish his residence in Washington, D.C., or any place other than Chicago; and never formed an intention to change his residence," Morris wrote.
Morris' ruling, issued just before 2 a.m. Thursday, came after a marathon three-day hearing last week in which Emanuel was grilled by a long parade of objectors to his candidacy, many of whom represented themselves and veered off into questions that had little to do with Emanuel's place of residence.
The serious, at times strange hearing explored the contents of the basement of Emanuel's home where he said he left many prized family possessions, including his wife's wedding dress - further proof he always intended to return to Chicago, he and his lawyers argued.
A former congressman from Chicago's North Side, Emanuel said he only moved his family to Washington because he couldn't turn down Obama's offer to be chief of staff. Emanuel's wife, Amy Rule, and the couple's three children still live in Washington and will remain there until the end of the school year.
The hearing focused heavily on Emanuel's home, with objectors contending he wasn't a resident partly because he rented out his house when his family joined him in Washington in the summer of 2009.
Emanuel said he leased his home for safety and security reasons. He tried to move back into his house when he returned to Chicago but the family renting it wanted $100,000 to break the lease and move out early. The tenant, businessman Rob Halpin, later filed paperwork to run for mayor against Emanuel, only to withdraw from the race a short time later.
Associated Press writers Deanna Bellandi and Erin Gartner contributed to this report from Chicago.