Chicago Mayor Rahm Emanuel failed to capture a majority of the vote in Tuesday's municipal election, forcing the former White House chief of staff into a potentially embarrassing runoff this spring against Cook County Commissioner Jesus "Chuy" Garcia.

The result exposed possible vulnerability for an incumbent who has widespread support from business leaders, national name recognition and millions of dollars in his campaign fund. He participated in half a dozen debates and forums and received a last-minute boost from President Barack Obama.

Still, he wasn't able to capture the more than 50 percent necessary to avoid an April runoff against Garcia, who finished far below Emanuel's vote total but far above the other three challengers.

Emanuel's challengers -- which included Cook County Commissioner Jesus Garcia, Alderman Bob Fioretti, businessman Willie Wilson and perennial candidate William Walls -- had hoped to capitalize on resident discontentment over Emanuel's handling of schools and city violence.

On the campaign trail, Emanuel said his first term saw some tough decisions and payoffs, including budgets that didn't rely on property tax increases, drawing business to the city, getting a longer school day and raising the minimum wage.

But his critics pointed to some of more tumultuous parts of his time in office, including the city's first teachers' strike in 25 years. The following year in 2013, he pushed for the closure of dozens of schools to save money, which angered parents and activists throughout the city's neighborhoods.

The Chicago Teachers Union -- whose fiery leader had once considered a bid to challenge Emanuel -- backed Garcia during the race as the alternative to Emanuel. The former state lawmaker enjoyed support from other unions and neighborhood groups.

The non-partisan election on Tuesday also featured contests for a new city treasurer, aldermen and advisory-style ballot questions on campaign finance and an elected school board.

Emanuel won his first mayoral race without a runoff four years ago after the retirement of Richard M. Daley, who held the job for more than two decades.