Resources for foreign aid come under attack when parties that care little for international affairs come to power. Internationally focused parties of the left and right, however, prefer to use aid as a tool to pursue their foreign policy goals. Yet varying goals based on left-right ideology differentiate the way donors use foreign aid. We leverage sector aid to test hypotheses from our Partisan Theory of Aid Allocation and find support for the idea that domestic political preferences affect foreign aid behavior. Left-internationalist governments increase disaster aid, while parochial counterparts cut spending on budget assistance and aid that bolsters recipients' trade viability. Conservative governments favor trade-boosting aid. We find consistent, nuanced, evidence for our perspective from a series of Error Correction Models and extensive robustness checks. By connecting theories of foreign aid to domestic politics, our approach links prominent, but often disconnected, fields of political research and raises important questions for policymakers interested in furthering the efficacy of development aid.Keywords: foreign aid allocation, donor ideology, internationalism, sectoral aid, domestic politics, OECD donor states, party politics, multi-dimensional preferences Foreign aid offers a potent instrument to incentivize recipient leaders' behavior, but its effectiveness has long been questioned.1 For many scholars, aid's patchy record in promoting democratization, growth, and cooperation stems from moral hazard and geopolitics: donors' strategic incentives diverted aid flows from the neediest or most deserving states and damaged their credibility. Analysis focused on which donor-states fell into this trap (Berthélemy and Tichit 2004), and on aid's expanded utility after the Cold War (Bearce and Tirone 2010). New 1 For a typology of "returns" to donor states, see Dudley and Montmarquette (1976). Morgenthau's (1962) essay exemplifies aid-for-policy skepticism.1 research, however, seeks to explain variation in aid efforts within countries over time. These studies open up the democratic donor state, substituting the domestic political preferences of governments for the amorphous "national interest", but find mixed support thus far (e.g. Noël and Therién 1995;Fleck and Kilby 2010; Dreher, Nunnenkamp and Schmaljohann 2014).Yet, foreign aid allocations likely reflect the goals of domestic decision-makers and consequently the preferences of key actors should influence foreign aid outputs (Tingley 2010, Milner and Tingley 2010, Fleck and Kilby 2010, Dreher, et al. 2014).We consider how partisan ideological preferences affect donors' allocation decisions across the array of foreign assistance sectors. We argue that parties' preferences predict their approach to foreign affairs. Changes in the preferences of governing parties produce shifts in allocation across aid types. Focusing on the effect of ideology on the most frequently used aid sectors allows detailed predictions that would be obscured by aggregate tren...