It feels odd saying “Karen Lewis for mayor of Chicago!” with a sense of complete seriousness.

It’s a phrase some Chicagoans have uttered many times since the 2012 Chicago Teachers Union strike. But it used to come out after a few beers among activists and fellow travelers, always accompanied by a smirk revealing the statement as a half-joke — fervently desired, but an impossible wish.

That smirk is still there, but now it’s more a look of disbelief that the hope might actually come true. A promising recent poll and a potential mayoral challenger’s dropout now have Lewis and much of the city thinking that she could actually beat Mayor Rahm Emanuel. “Mayor 1%,” long thought impervious to a challenge from anyone, could suffer a second major defeat by Lewis and the CTU during his time as mayor — not in a labor fight, but in his reelection bid.