Previous studies indicate that political parties abroad influence election strategies in European democracies. This research explores whether transnational party alliances—beyond just being a successful incumbent—increase this impact. By analyzing party manifestos and employing spatial econometric analyses across the EU, we find belonging to the same EP group significantly enhances learning from foreign parties' policy positions. The effect is magnified when those parties are also part of an alliance; estimated impacts range up to three times higher than with non-aligned incumbents in both short-term and long-term scenarios. Our findings highlight that established transnational ties may be a more potent driver for international policy emulation among national parties than general success alone.
