Local politicians are expected to mobilize voters for national party candidates, but this effort proves challenging due to monitoring difficulties and rewards' credibility issues.

The study employs a formal model showing that local incentives depend on copartisan officials' proportion. More colleagues mean greater district capture chances yet reduces individual impact, disincentivizing effort.

Using Mexican federal election data (2000-2012), the findings validate this theory: parties do not gain significant mobilization advantages from controlling multiple offices simultaneously.