While traditional models of electoral competition assumed constraint to one ideological dimension, more recent models expand the political space to a multitude of issue dimensions. We adopt a perspective lying in between these two approaches. Electoral competition is structured by issue packages – combinations of a limited number of issues that are not only promising electorally to each party, but also maximize synergies with other package components. Issue packages unite the best of both model worlds: Like unidimensionality, they emphasize the need for integrated policy platforms and respect voters’ limited processing capacity; like multidimensionality, they reflect the complexity of an increasingly diversified issue landscape and capture dynamic campaign incentives. Using a new comparative dataset linking representative mass surveys from six European countries with Twitter analysis of campaign activity, our analysis shows that issue emphasis in campaign platforms is better explained by a model that takes the synergies between issues in potential packages into account, compared to a model of multiple, but separate issues. Our theory explains why electoral competition remains relatively structured, while at the same time embracing intricate maneuvering.
