Why do some declining industries easily receive the benefits of trade restriction whereas others not? How do elected officials determine industrial sectors to protect? While illuminating several factors that create inter-industry variations in protection, economists regard trade-policy outcomes as a function of lobbying and campaign contributions of import-competing sectors. To redress this gap, this paper analyzes the influence of electoral competition on the inter-industry structure of protection. I argue that all things being equal, sectoral variations in protection is explained by party unity, the extent to which parties act cohesively as strategic units and serve the interest of their core-partisan groups. Party unity, by shaping electoral values of party labels and personal reputations to reelection-minded politicians, determines types of electoral constituencies whom legislators are likely to target in policy decisions. The higher party unity over trade issues, the more likely is the incumbent-party to serve the interest of their core-partisan groups by protecting industries and sectors in their partisan strongholds rather than those in pivotal regions. These hypotheses will be tested with a variety of statistical methods, employing data on trade protection and district-level elections in the United States and Canada. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]