To topple Mayor Rahm Emanuel, his challengers need to keep him under 50 percent in the first round of voting.
  • Al Podgorski / Sun-Times Media
  • To topple Mayor Rahm Emanuel, his challengers need to keep him under 50 percent in the first round of voting.

Now that Alderman Bob Fioretti has announced he’s running for mayor, it’s a good time to remind you—once again—that we have a runoff system for electing mayors in Chicago.

That is, mayoral candidates have to win more than 50 percent of the vote to get elected.

I know a lot of folks don’t realize this because I’ve been getting calls and e-mails exclaiming that Fioretti and Karen Lewis—should she actually jump into the race—will split the anti-Rahm vote.

And this, they say, will guarantee the reelection of Mayor Emanuel, who will be free to fire all the librarians, teachers, and janitors he hasn’t already fired.

I understand why so many Chicagoans are confused.

As much as I love this city and its residents, I must concede that once an idea gets fixed in our brains, it’s very hard to extricate or alter it.

In this case, our fundamental impression of Chicago politics goes back to the legendary three-candidate Democratic mayoral primary of 1983—which was before some of you were even born.

That’s when Harold Washington (the “black candidate”) eked out a victory because Jane Byrne and Richie Daley (the “white candidates”) split the white vote.

The takeaway for Chicagoans—white as well as black—was most definitely not to bridge the differences between the races so we can all just get along.

No, the lesson most people learned was to make sure that, from that point forward, no one race would ever risk splitting its racial base by going into an election with more candidates than the other race.

For that reason, the ’90s came and went without any prominent white candidate daring to run against Mayor Daley, for fear of being the one who split the white vote. Similarly, it was almost comical to watch black politicians maneuver every four years to try and become the consensus black candidate.

It’s no wonder that a real smart politician like Barack Obama took one look at this cesspool and said get me the hell out of Dodge!

Breaking news, Chicago: we haven’t had a primary system of electing a mayor since the 1990s, when state legislators changed the rules.

Since then, we’ve had what they call a nonpartisan system. And they call it that because there are no Democratic or Republican primaries.

Instead, we have a general election in February in which candidates run without any party label. If no candidate emerges with more than 50 percent of the vote, the top two finishers go at it in a winner-take-all runoff.

Hence the name: a runoff system!

Soooo . . .

It doesn’t matter if Bob Fioretti or Karen Lewis or Bob Shaw or Amara Enyia or Brian Urlacher (why not?—the dude just quit his TV gig) are aiming for the same anti-Rahm vote.

The only real issue is whether the anti-Rahm vote outnumbers the pro-Rahm one.

If so, Mayor Rahm won’t get the 50-percent-plus-one vote he needs to win outright. And we go to the runoff.

So you might say that Fioretti, Shaw, Enyia, et al are running to finish second.

Actually, in my moments of delusion, I convince myself that the anti-Rahm vote is so large that Rahm won’t even make the runoff.

Just blame it on the aftershock of that marijuana-laced gummy bear I popped in the Nevada desert.

As you can imagine, I’ve been compulsively discussing this topic for weeks with just about everyone I meet. Some folks—in particular, Frank Avila, the political operative—are quick to point out that it’s possible to have too many anti-Rahm rivals in the race.

In other words, too many candidates will confuse the Chicago electorate—which, let’s face it, is not all that bright to begin with—and thus help Rahm.

This is sort of what happened in the last mayoral go-around, when Carol Moseley Braun made a colossal fool of herself by saying Patricia Van Pelt Watkins was “strung out on crack.”

Just another one of our finer electoral moments.

So if you see Bob ripping into Karen or Karen ripping into Bob you might start to wonder—are they just in it to elect Rahm?

Anything’s possible in Chicago.

Anyway, here’s my parting advice, voters: vote for whomever you want.

If all goes well, we’ll have the runoff election in April, when the real fun will start.