Watch your back in your ward.

In Rahm Emanuel's Chicago, aldermen are deemed a necessary nuisance, while all power vests in the mayor and his cronies.

In their respective wards, the 50 aldermen deem the post of Democratic ward committeeman to be an irritating nuisance. With Rich Daley's departure, the "clout" attached to the committeeman's post has shriveled from insignificant to negligible.

But no alderman wants anyone else in the committeeman's job. It's positively Darwinian: Not just survival of the species, but preemptive eradication of all rival species.

"I'm watching my back," said newly elected 36th Ward Alderman Nick Sposato. "If I don't have the (committeeman's) job, whoever does will create opposition to me." In the 36th Ward, longtime Democratic powerhouse Bill Banks, who had been the committeeman since 1981, is retiring in the wake of Sposato's monumental April upset of John Rice, Banks' hand-picked successor as alderman. Sposato said that he's running for committeeman in the March 2012 election.

Predictably, challengers who beat the sitting alderman/committeeman or the committeeman's choice for alderman run the next year for committeeman. Aldermanic winners in the 2nd, 3rd, 7th, 15th, 16th and 20th wards in 2007 finished the job in 2008, ousting the discredited former alderman as committeeman. Overall, 26 of the 50 aldermen are Democratic committeemen, two have their spouse as the committeeman, and one has his sister as the committeeman.

Much like the animal kingdom, there is a definite hierarchy and food chain among the committeemen. The heap looks like this:

Bulls: For these aldermen/committeemen, their ward is their kingdom, they rule with an iron fist, and they brook no opposition. Patronage may no longer be plentiful, but they have a loyal cadre of workers, have their precincts covered, and can raise up to $100,000 annually. The most domineering of the "bulls" are Dick Mell (33rd), Ed Burke (14th) and Pat O'Connor (40th), whose power extends beyond their wards. Another 23 committeemen, of varying degrees of seniority and political acuity, rank in this category. All but three seized the committeemanship after being elected alderman to protect their power base.

Those three -- Mary O'Connor (41st), Michele Smith (43rd) and Matt O'Shea (19th) -- reversed the process: They were elected Democratic committeeman in 2008 and used their election as a springboard to win open 2011 aldermanic races.

In the April election, two venerable Northwest Side "bulls," Banks and retiring Aldermen Pat Levar (45th), were pastured with the sheep after their aldermanic choices lost. Levar, however, says that he is going to run for his party post in 2012.

Expect freshman Aldermen Proco Joe Moreno (1st), Will Burns (4th), Roderick Sawyer (6th), Mike Chandler (24th), Jason Ervin (28th), Deborah Graham (29th), John Arena (45th), James Cappleman (46th), Harry Osterman (48th) and Sposato to attempt to rise to the "bull" level next year.

Stallions: For this select group of committeemen, being an alderman is a regression. Their elected post far exceeds that of an alderman in clout. They dictate the alderman in their ward. Among this group are Illinois House Speaker Mike Madigan (13th), Secretary of State Jesse White (27th), county Assessor Joe Berrios (31st), county Commissioner John Daley (11th) and former congressman Bill Lipinski (23rd). Past committeemen who exercised similar clout were Ed Kelly (47th), Tom Hynes (19th), Dan Rostenkowski (32nd) and George Dunne (42nd).

For "stallions," their hand-picked alderman is a "lamb" who can be readily sheared and replaced upon the slightest evidence of disloyalty or ingratitude. Among the council's "lambs," who exist under the oppressive thumb of their committeeman, are Marty Quinn (13th), James Balcer (11th), Mike Zalewski (23rd), Walter Burnett (27th) and Ray Suarez (31st). Until they emerge as their ward committeeman, they'll always be viewed as a pawn, not a player.

Donkeys: For this select and stubborn group, being a committeeman means their political domain is all that they can see . . . from their back porch. They don't control the alderman. The alderman ignores them. An example is Tom Sharpe (46th), the erstwhile ally of former alderman Helen Shiller. Sharpe backed a loser in the aldermanic race this year, and Cappleman is sure to oust him next year. Another example is the 49th Ward's obscure David Fagus, who vegetates in the shadow of Alderman Joe Moore, who runs his ward imperiously. Moore postures as an "independent, progressive Democrat," deems being a committeeman detrimental to that image, and so keeps a lamb as committeeman.

An oddity is John Fritchey, a county commissioner and the 32nd Ward Democratic committeeman -- sort of a donkey in sheep's clothing. Fritchey tepidly backed Scott Waguespack for alderman in 2007 against the Rostenkowski-Gabinski organization choice. Waguespack won, and they soon became estranged. Fritchey couldn't oust the alderman in 201l, and Waguespack doesn't care who the committeeman is.

Family ties. It's impolite to specify the lion and the lamb, but an alderman whose spouse or sibling is the committeeman won't get sheared. The husbands of Aldermen Marge Laurino (39th) and Debra Silverstein (50th) are committeemen, as is the sister of Alderman Tim Cullerton (38th). On the South Side, U.S. Representative Jesse Jackson Jr., in order to shore up his power base in the 7th Ward, ran his wife, Sandi Jackson, for alderman in 2007 and for committeeman in 2008; she won both races.

Here's a look at developing area contests:

36th Ward: Banks, who was the chairman of the City Council Zoning Committee for nearly 20 years, retired in 2009 and prevailed on Daley to appoint his driver and aide, John Rice, as his successor. Rice proved to be an inept campaigner and an indifferent fund-raiser, and he was upset by Sposato by a 1,228-vote margin on April 5.

Banks announced in June that he would not seek reelection as committeeman in 2012. Banks and his ally, former state senator Jim DeLeo, had built a political machine in the ward, and as recently as 2009 the two had close to $2 million in their campaign accounts. Banks was unopposed for alderman in 2007 and for committeeman in 2008, and DeLeo never had an opponent in six elections. Now, their machine has all but evaporated.

Banks likely will support Larry Andolino, an area attorney. Sposato, asked how he can run to replace Banks when he promised to be independent of the machine, replied, "Voters understand. I can't do my job (as alderman) if the committeeman is sabotaging me." My prediction: In 2012 Sposato will eradicate the wheezing, gasping Banks-DeLeo machine.

45th Ward: "Of course he's running for committeeman in 2012," said Manuel Galvan, Levar's press spokesman. "He's upbeat. His health is improving. He has no need to leave. He will continue in politics."

Is this a feint, a bluff or a blunder? Remember this: After Aug. 1 the City Council will commence drawing new ward boundaries, taking effect in 2012. The aldermen elected in 2011 will serve through 2015 in their existing wards, while the committeemen elected in 2012 will run in the new wards.

John Arena, who was elected by 30 votes, touts himself as a "progressive Democrat," and he was the Northwest Side's 2011 rags-to-riches Cinderella story. He wasn't supposed to win, but, depending on the ward remap, he may soon turn into a pumpkin. Arena, Levar, Tim Cullerton and 38th Ward Democratic Committeeman Patti Jo Cullerton all reside in Portage Park, within eight blocks of each other. The Cullertons and Levar are tight allies.

The south half of the 38th Ward will be collapsed into a new Hispanic-majority ward, which will absorb Montclare and other parts of Sposato's ward. The council's mapmakers, led by Mell, have a quandary: Do they keep Portage Park split along Laramie Avenue and run Cullerton's ward west along Irving Park Road to take in Galewood and the Cumberland Avenue corridor in the 36th Ward and Oriole Park in the 41st Ward? Or do they lump Arena and Cullerton in the same ward, encompassing Portage Park, Jefferson Park, Gladstone Park and points west along Irving Park?

Before the election, Arena pledged not to run for committeeman, but after he won, he began wobbling. Told that Levar was running and asked what his plan is, Arena said, "I need time to think about it. I'll give you my decision over the weekend." Despite repeated phone calls to Arena, no reply was forthcoming. Smart move. Mum's the word.

Arena's only leverage is the possibility that he can beat Levar for committeeman, and his only salvation is to cut a deal with Levar, promise not to run in 2012, and fervently hope that Levar can preserve his existing ward. If Arena announced against Levar, he'd be put into a ward with the Cullertons, Levar would retire, the still-potent 38th and 45th Ward Democratic organizations would meld into one, and all that labor union money which flowed to Arena in 2011 would devolve upon Patti Jo Cullerton in 2012 and Tim Cullerton in 2015.

 In the 45th Ward, the "Year of the Lamb" has dawned. The only question is: Who's shearing whom?