This paper explores the outcome of the noncooperative environmental decision-making under transnational externalities when the national policies are chosen by the elected politicians. Specifically, we re-examine the extent of a voter's incentives for supporting politicians who are less green than he is, a phenomenon called "political race to the bottom". The median voter (principal) strategically appoints his delegate (agent) who independently decides the level of environmental investments (as inputs for the global public good) which generate transnational benefits. The new feature of our model is the introduction of complementarity between public inputs, while previous studies supposed perfect substitution. Our analysis derives some new results. The extent of \political race to the bottom" diminishes as public inputs become more complementary, and if its degree exceeds a certain point, "political race to the top" emerges, without supposing effects of other factors including international trade. We further examine the case with perfect substitution. Equilibrium is in fact asymmetric. Although one of the elected politicians pays no attention to the environment, the other country results in self-representation.