In the

 United States Court of Appeals
                For the Seventh Circuit

No. 10-1215

P ABLO D ELAPAZ and
M ICHAEL S ARKAUSKAS,
                                                 Plaintiffs-Appellants,
                                   v.

R OBERT R ICHARDSON,
                                                  Defendant-Appellee.


              Appeal from the United States District Court
         for the Northern District of Illinois, Eastern Division.
              No. 07 C 1224—George M. Marovich, Judge.



    A RGUED D ECEMBER 8, 2010—D ECIDED F EBRUARY 14, 2011




 Before F LAUM and E VANS, Circuit Judges, and M C C USKEY,
District Judge.Œ
  F LAUM, Circuit Judge. Appellants Pablo Delapaz and
Michael Sarkauskas work for the City of Chicago’s De-
partment of Streets and Sanitation (“DSS”). Under DSS


Œ
 The Honorable Michael P. McCuskey, United States District
Court for the Central District of Illinois, sitting by designation.
2                                                 No. 10-1215

Commissioner Al Sanchez, Delapaz and Sarkauskas
were temporarily assigned to “act up”—meaning to
work above their titled position for additional pay.
Shortly after Michael Picardi replaced Sanchez as DSS
Commissioner, appellee Robert Richardson (the Deputy
Commissioner of the Bureau of Street Operations) in-
formed Delapaz that he was being returned to his titled
position. Richardson told Delapaz to inform Sarkauskas
that he too would be returned to his titled position.
Appellants contend that Richardson demoted them
because of their political affiliation with the Hispanic
Democratic Organization (“HDO”), while Richardson
maintains that he simply was carrying out Picardi’s
directive that all acting employees be returned to their
permanent positions.
  Delapaz and Sarkauskas brought this suit against
Richardson (and others, who we need not consider in
this appeal) under 42 U.S.C. § 1983. The suit charges
that Richardson violated their First Amendment right to
free association by demoting them on the basis of their
political affiliation. The district court granted summary
judgment in favor of Richardson; Delapaz and Sarkauskas
appealed.
    For the reasons set forth below, we affirm.


                       I. Background
  Appellants both are long-time City employees. Delapaz
has been employed by the City since 1984, and has held
the position of foreman of motor truck drivers in the DSS
No. 10-1215                                              3

since 1998. Sarkauskas began working for DSS as a
motor truck driver (“MTD”) in 1979. Both Delapaz and
Sarkauskas have volunteered for the HDO. Delapaz has
done so since 1996 or 1997, Sarkauskas, since 2001.
  At times, the City assigns current employees to fill
open positions above their official titled positions for a
limited time. For example, an MTD might be assigned to
be an acting foreman of MTDs. That practice is known
as “acting up.” In 2001, then-DSS Commissioner
Sanchez assigned Sarkauskas to be an acting foreman in
the Bureau of Sanitation, one of seven bureaus within the
DSS. In 2002, Sanchez made Delapaz acting General
Foreman of the Bureau of Street Operations, another DSS
bureau. Later, Sanchez transferred Sarkauskas to the
Bureau of Street Operations, where he worked directly
under Delapaz as an acting foreman.
  In June 2005, Picardi became DSS Commissioner, and
Richardson was named Deputy Commissioner of the
Bureau of Street Operations. Picardi testified that, as DSS
Commissioner, he had the authority to assign employees
to “act up” in title and to return employees from acting
positions to their titled positions. According to Picardi,
shortly after he became Commissioner, he ordered all
acting employees returned to their permanent positions
because of “budgetary and operational necessity.” Richard-
son testified that in June 2005 Picardi directed him to
inform all Bureau of Street Operations employees who
were acting up that they would be returned to their titled
positions. Picardi testified that he made an exception to
that sweeping order for purposes of snow removal,
4                                               No. 10-1215

authorizing Richardson to assign MTDs and MTD fore-
men to “act up” as necessary to clear snow. Picardi
further testified that he delegated his authority re-
garding “acting up” decisions to the Deputy Commis-
sioners, including Richardson.
  In the summer of 2005, Richardson told Delapaz he
would no longer be acting up, and would return to his
position as MTD foreman. According to Delapaz, during
that conversation Richardson said, “You know, Pablo,
you are no longer the General Foreman. As a matter of
fact, you are in charge of nothing, and your guy is gone.”
Delapaz testified that he did not know whether Richard-
son was aware that he volunteered for the HDO, and
that Richardson did not indicate who he meant by
“your guy.” Two weeks later, at Richardson’s direction,
Delapaz informed Sarkauskas that he would no longer
be an acting foreman. Sarkauskas testified that all ten of
the acting MTD foremen in the Bureau of Street Opera-
tions were returned to their titled positions as MTDs at
that time. Sarkauskas further testified that not all of
those individuals were affiliated with the HDO.
  The following fall, Richardson assigned Rodney Sernek
to act as a general foreman during the hours needed for
snow removal only. Sernek had made contributions to
and done campaign work for Alderman Richard Mell,
despite the fact that he did not live in the Alderman’s
ward. Delapaz contends that Sernek “replaced” him as
quid pro quo for Sernek’s support of Mell. Sarkauskas
testified that after he was returned to his titled position,
Daniel Gasdziak was made an acting foreman, and that
No. 10-1215                                               5

Gasdziak held that position for a year and a half. Ac-
cording to Richardson, he did not assign Gasdziak to
act up until April 30, 2006.
  Richardson testified that he neither knew that Sernek
was affiliated with Alderman Mell, nor whether Delapaz
or Sarkauskas was affiliated with any political organiza-
tion. Richardson also testified that he is not affiliated
with and has not made political contributions to
Alderman Mell.
  Delapaz and Sarkauskas claim that their First Amend-
ment rights were violated when they were returned to
their titled positions (“demoted” in their words) be-
cause they belonged to the HDO and did not support
Alderman Mell. The district court granted summary
judgment in favor of Richardson, and Delapaz and
Sarkauskas appeal.


                      II. Discussion
   We review the district court’s grant of summary judg-
ment de novo, construing all facts and reasonable infer-
ences in the light most favorable to Delapaz and
Sarkauskas. Forrest v. Prine, 

, 742-43 (7th Cir.
2010). A grant of summary judgment is appropriate
when no genuine issues of material fact exist, and the
moving party is entitled to judgment as a matter of law.
F ED. R. C IV. P. 56(c); Anderson v. Liberty Lobby Inc., 

, 255 (1986).
  An individual’s affiliation with a political party enjoys
First Amendment protection. See Gunville v. Walker, 583
6                                                No. 10-1215

F.3d 979, 984 (7th Cir. 2009). The firing or demotion of an
employee based on party affiliation violates the First
Amendment. 

exception exists for jobs
that cannot be performed effectively without party
loyalty, the parties agree that political affiliation is not
an appropriate consideration for appellants’ DSS posi-
tions. 

the merits of appellants’ First Amend-
ment claim, we consider the viability of their § 1983
claim more generally. To survive summary judgment, a
plaintiff claiming a violation of § 1983 must produce
evidence that the defendant “caused or participated in
[the] constitutional deprivation.” Vance v. Peters, 

, 991 (7th Cir. 1996). See also Caldwell v. City of Elwood,

, 672 (7th Cir. 1992) (section 1983 plaintiff
must “ ‘connect the violation to the named defendants’ ”)
(quoting Brownlee v. Conine, 

, 354 (7th Cir.
1992)). Here, appellants admitted in their Local Rule 56.1
response, that “Picardi ordered that all employees who
were currently acting up in a higher rated position . . . be
returned to their titled positions, except to the extent
necessary for specific operational needs.” Presumably
in reliance on that admission, the district court believed
it to be “undisputed that the decision to demote
Delapaz and Sarkauskas was made by Picardi, not by
Richardson.” Appellants now argue that the district
court got it wrong. Ignoring their own admission, appel-
lants point to another paragraph in their 56.1 response,
in which they denied that Picardi told Richardson to
inform Delapaz and Sarkauskas about their demotions.
Appellants based that denial on Picardi’s statement that
No. 10-1215                                              7

he delegated the authority to assign employees to “act up”
in title and to return employees to their career service
titles to the Deputy Commissioners of the seven DSS
bureaus.
  Rule 56.1(b)(3) of the Local Rules for the Northern
District of Illinois requires parties opposing a sum-
mary judgment motion to file a concise response to
each numbered paragraph in the moving party’s Local
Rule 56.1 statement. The obligation set forth in
Local Rule 56.1 “is not a mere formality.” Waldridge
v. American Hoechst Corp., 

, 924 (7th Cir.
1994). Rather, “[i]t follows from the obligation imposed
by Fed. R. Civ. P. 56(e) on the party opposing sum-
mary judgment to identify specific facts that establish
a genuine issue for trial.” 

is designed, in
part, to aid the district court, “which does not have
the advantage of the parties’ familiarity with the record
and often cannot afford to spend the time combing
the record to locate the relevant information,” in deter-
mining whether a trial is necessary. 

  Here, the district court relied on appellants’ admission,
as it was entitled to do. We, too, are entitled to rely on
that admission, and are inclined to hold appellants to
their 56.1 response. In light of their admission that
Picardi made the demotion decision, appellants cannot
establish § 1983 liability against Richardson.
  Even if we were to disregard the admission, appel-
lants’ § 1983 claim fails because they waived the issue
of Richardson’s personal involvement in the demotion
decision. In his summary judgment brief, Richardson
8                                                No. 10-1215

argued that appellants had failed to demonstrate that
he participated in the decision to demote them. As the
district court noted, appellants did not address that
argument in their response brief below. Consequently,
they waived the issue. See Hicks v. Midwest Transit, Inc., 

, 652 (7th Cir. 2007) (arguments not raised
before the district court are waived on appeal).
   Moreover, appellants’ § 1983 claim cannot survive
summary judgment for the additional reason that they
have not demonstrated the existence of a genuine issue
for trial as to Richardson’s involvement. Appellants rely
on Picardi’s statement that he delegated the authority
to make acting up decisions to the Deputy Commis-
sioners, including Richardson. However, that statement
is not in conflict with Picardi and Richardson’s testimony
that, immediately upon assuming responsibility as
DSS commissioner, Picardi decided to return all em-
ployees who were acting up to their titled positions.
Picardi may have initially ordered all acting employees
returned to their titled positions, and thereafter
permitted Deputy Commissioners to assign employees
to “act up.”
  Apart from their inability to establish § 1983 liability
against Richardson, appellants failed to make out a
prima facie claim for violation of their First Amendment
rights. To establish a prima facie First Amendment claim,
public employees must present evidence that (1) their
speech was constitutionally protected; (2) they suffered
a deprivation likely to deter free speech; and (3) their
speech was the but-for cause of the employer’s actions. See
No. 10-1215                                               9

; Fairley v. Andrews, 

,
525-26 (7th Cir. 2009) (requiring but-for causation). Only
the third element—causation—is at issue here. We have
held that, to demonstrate causation in this context, plain-
tiffs must show that the defendant knew of their party
affiliation. 

.
  In an effort to demonstrate that Richardson knew
Delapaz was affiliated with the HDO, appellants point
to the “your guy” comment. Construing all facts and
reasonable inferences in the light most favorable to ap-
pellants, it can reasonably be inferred that Richardson
was referring to Sanchez. However, appellants’ brief on
appeal never addresses Sanchez’s relationship to the
HDO, or Richardson’s knowledge of any such relation-
ship. Nor did appellants link Sanchez to the HDO in the
brief in opposition to summary judgment or the 56.1
statement they filed in the lower court. Summary judg-
ment is the “put up or shut up” moment in litigation.
Goodman v. National Sec. Agency, Inc., 

, 654
(7th Cir. 2010). As such, appellants were required to
present evidence on which a reasonable jury could rely
tending to prove their claim. 

present no evidence linking Sanchez—Delapaz’s
“guy”—to the HDO, no jury could conclude that Richard-
son demoted Delapaz because of his political affiliation
with the organization.
  Appellants present no evidence that Richardson
knew Sarkauskas was affiliated with the HDO. Instead,
Sarkauskas contends that the timing of his demotion—
two weeks after Delapaz’s—is suspicious. However, it is
10                                            No. 10-1215

unclear how that timing is at all suspicious, particularly
because nine other MTDs—some of whom Sarkauskas
admits were not affiliated with the HDO—also were
returned to their titled positions at that time. In short,
Sarkauskas presents nothing more than his own unsub-
stantiated speculation as to the reason for his demo-
tion; such conjecture alone cannot defeat a summary
judgment motion. Rockwell Automation, Inc. v. National
Union Fire Ins. Co. of Pittsburgh, 

, 757 (7th
Cir. 2008).


                    III. Conclusion
  For the foregoing reasons, we AFFIRM the dis-
trict court’s grant of summary judgment in favor of
Richardson.




                          2-14-11