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Partial researchResearch snapshot 2026-09-13. Evidence gaps remain; see Coverage for requirements.

Office briefing

TLACOLULA DE MATAMOROS — Municipal government

Tracked current office. Identifiers stay separate from display names.

Mexico · TLACOLULA DE MATAMOROS / OAXACA · municipal · Municipal governmentMX-M-20-550

Read the complete original research briefing

INE result distributions kept separate. Certified seats, supplementary elections, coalition and boundary audit remain.

1. What office, where, and when is the next election?

Geography
TLACOLULA DE MATAMOROS / OAXACA
Next election
2027-06-06
Linked upcoming event
next-05dfd1e5ad53ffec71db91ce
Registry qualification
Unknown

2. How certain is that date?

2027-06-06 is expected (not formally called). Day precision. A date without a formal call is not confirmed.

3. Who won earlier selected elections?

2024

Special · Legal certification not established · candidate marks

  • PT26.3%
  • MORENA24.0%
  • CAND_IND314.4%
  • PRI9.6%
  • MC6.9%
  • PVEM4.2%
  • FXMO4.0%
  • NAO1.8%
  • MUJER1.7%
  • PAN1.3%
  • PRD0.5%
  • PUP0.5%
  • C_PAN_PRI_PRD0.4%
Results for event-ba7bc57cfde49e9372ddc192
Label / candidateParty codeVotesShareSeatsStatus
PTmexico/S62a5cc2e3b/20243,47426.3%UnknownRecorded
MORENAmexico/S62a5cc2e3b/20243,16724%UnknownRecorded
CAND_IND3mexico/S62a5cc2e3b/20241,90314.4%UnknownRecorded
PRImexico/S62a5cc2e3b/20241,2709.6%UnknownRecorded
MCmexico/S62a5cc2e3b/20249076.9%UnknownRecorded
PVEMmexico/S62a5cc2e3b/20245584.2%UnknownRecorded
FXMOmexico/S62a5cc2e3b/20245264%UnknownRecorded
NAOmexico/S62a5cc2e3b/20242321.8%UnknownRecorded
MUJERmexico/S62a5cc2e3b/20242191.7%UnknownRecorded
PANmexico/S62a5cc2e3b/20241761.3%UnknownRecorded
PRDmexico/S62a5cc2e3b/2024680.5%UnknownRecorded
PUPmexico/S62a5cc2e3b/2024610.5%UnknownRecorded
C_PAN_PRI_PRDmexico/S62a5cc2e3b/2024490.4%UnknownRecorded

2021

Special · Legal certification not established · candidate marks

  • PT31.8%
  • PAN_PRI_NAO_124.2%
  • MORENA15.2%
  • MC13.2%
  • PUP7.1%
  • FXM3.5%
  • PRD1.6%
  • PES0.6%
Results for event-59789af383c91787cedc798f
Label / candidateParty codeVotesShareSeatsStatus
PTmexico/Sdcf38dc0c1/20213,68031.8%UnknownRecorded
PAN_PRI_NAO_1mexico/Sdcf38dc0c1/20212,80424.2%UnknownRecorded
MORENAmexico/Sdcf38dc0c1/20211,75815.2%UnknownRecorded
MCmexico/Sdcf38dc0c1/20211,52213.2%UnknownRecorded
PUPmexico/Sdcf38dc0c1/20218267.1%UnknownRecorded
FXMmexico/Sdcf38dc0c1/20214093.5%UnknownRecorded
PRDmexico/Sdcf38dc0c1/20211901.6%UnknownRecorded
PESmexico/Sdcf38dc0c1/2021750.6%UnknownRecorded

2018

Special · Legal certification not established · candidate marks

  • PT_MORENA_ES46.1%
  • PRI_PVEM_PANAL23.0%
  • PAN_PRD_MC21.7%
  • PMR3.4%
  • PUP2.2%
  • PSD0.5%
Results for event-df199eecfd246c848c1b219c
Label / candidateParty codeVotesShareSeatsStatus
PT_MORENA_ESmexico/S9390e653f6/20185,17046.1%UnknownRecorded
PRI_PVEM_PANALmexico/S9390e653f6/20182,58323%UnknownRecorded
PAN_PRD_MCmexico/S9390e653f6/20182,44021.7%UnknownRecorded
PMRmexico/S9390e653f6/20183823.4%UnknownRecorded
PUPmexico/S9390e653f6/20182522.2%UnknownRecorded
PSDmexico/S9390e653f6/2018560.5%UnknownRecorded

4. Competition and volatility

competition index

Provisional imported-series CI

69.150–100 historical closeness

Actual-event and/or comparability review incomplete

Comparison status: Provisional imported-series comparison; actual-event review open

Method ci.weighted-gap.v1. Inputs: latest_gap=2.4345757335448077, oldest_gap=23.771019020490673, previous_gap=7.776988636363637

pedersen volatility

Provisional volatility

25.4percentage points

Grouped Pedersen lower bound (percentage points). Seven exact standalone INE party labels. Joint coalition combinations, independents and other parties remain Other, without allocating coalition votes. This coarse grouped comparison can conceal coalition-member shifts and requires the stated geographic/event review. An interval is withheld if either election has no list mapped to an explicit named group. This is aggregate share change, not individual voter switching. Event review: Actual-event and/or comparability review incomplete

Comparison status: Latest interval

Method pedersen.grouped.v1. Inputs: groups=["PAN","PRI","PRD","PT","PVEM","MC","MORENA","Other"], interval=Latest interval, vectors=[[1.3957176843774781,10.07137192704203,0.5392545598731165,27.549563838223634,4.425059476605869,7.192704203013482,25.114988104678826,23.711340206185564],[0,0,1.6867897727272727,32.67045454545455,0,13.512073863636363,15.607244318181818,36.5234375],null]

pedersen volatility

Withheld volatility

Unknownpercentage points

Grouped Pedersen lower bound (percentage points). Seven exact standalone INE party labels. Joint coalition combinations, independents and other parties remain Other, without allocating coalition votes. This coarse grouped comparison can conceal coalition-member shifts and requires the stated geographic/event review. An interval is withheld if either election has no list mapped to an explicit named group. This is aggregate share change, not individual voter switching. Event review: Actual-event and/or comparability review incomplete

Comparison status: Previous interval · Comparable grouped vectors unavailable for this interval

Method pedersen.grouped.v1. Inputs: groups=["PAN","PRI","PRD","PT","PVEM","MC","MORENA","Other"], interval=Previous interval, vectors=[[1.3957176843774781,10.07137192704203,0.5392545598731165,27.549563838223634,4.425059476605869,7.192704203013482,25.114988104678826,23.711340206185564],[0,0,1.6867897727272727,32.67045454545455,0,13.512073863636363,15.607244318181818,36.5234375],null]

pedersen volatility

Withheld volatility

Unknownpercentage points

Grouped Pedersen lower bound (percentage points). Seven exact standalone INE party labels. Joint coalition combinations, independents and other parties remain Other, without allocating coalition votes. This coarse grouped comparison can conceal coalition-member shifts and requires the stated geographic/event review. An interval is withheld if either election has no list mapped to an explicit named group. This is aggregate share change, not individual voter switching. Event review: Actual-event and/or comparability review incomplete

Comparison status: Both intervals mean · Comparable grouped vectors unavailable for this interval

Method pedersen.grouped.v1. Inputs: groups=["PAN","PRI","PRD","PT","PVEM","MC","MORENA","Other"], interval=Both intervals mean, vectors=[[1.3957176843774781,10.07137192704203,0.5392545598731165,27.549563838223634,4.425059476605869,7.192704203013482,25.114988104678826,23.711340206185564],[0,0,1.6867897727272727,32.67045454545455,0,13.512073863636363,15.607244318181818,36.5234375],null]

Source-reported control: Unverified. Current tenure requires separate dated evidence.

5. Officeholder evidence

Dated roster observations are not automatically current tenure. The source current-office flag means this office is tracked now, not that the last winner still holds it.

No officeholder observation supplied.

6. Polling context

No local poll supplied.

7. Unresolved issues and sources

No open research issues attached to this office.

Sources

Cite this record

Center for Digital Democracy. “TLACOLULA DE MATAMOROS — Municipal government.” Subnational Election Observatory, releaselatin-america-fe5e91689def, snapshot 2026-09-13. /electiondatabase/offices/MX-M-20-550. Sources: mexico--url-3635e08ffbefd711526cbeea, mexico--S62a5cc2e3b, mexico--Sdcf38dc0c1, mexico--S9390e653f6.