Generic Frameworks for Ranked Fusion Voting

We introduce two generic frameworks for ranked fusion voting: Tagged RankedFusion Voting (TRFV) and Line-Ranked Fusion Voting (LRFV). In TRFV, vot-ers rank candidates and assign one party tag to each ranked candidate; in LRFV,voters rank candidate–party lines directly. Both frameworks are modular ratherthan self-contained, and must therefore be instantiated with an underlying rankedvoting rule on candidates. We formalize this architecture through a collapseoperator that maps fusion ballots to the candidate-level inputs required by theunderlying rule. For ranked rules based on candidate orderings, first-occurrencecollapse provides a natural implementation. We present this collapse not asan exhaustive characterization of all admissible collapses, but as the simplestcanonical construction satisfying the baseline constraints relevant to candidate-order-based ranked rules. We show that the resulting framework reduces to theunderlying ranked rule when fusion is absent, is invariant at the candidate levelunder intra-candidate party refinement, and embeds TRFV as a restricted specialcase of LRFV. The framework applies to both single-seat and multi-seat settingsand accommodates party attribution without altering candidate-level selection.