Presidential Voting in the 2016 US Presidential Election: Impacts of the US-Mexico Border and Border Integration

The 2016 presidential election brought many proposals to the fore, several with potentially significant impacts in the US-Mexico border region. Republican candidate, Donald Trump, promised to build a border wall, return manufacturing jobs to the US, impose import tariffs, and scrap or renegotiate existing trade agreements, including the North American Free Trade Agreement (NAFTA). This paper examines county-level presidential voting in the four US states bordering Mexico. Two hypotheses are tested. One, in general, that voters in Mexico-adjacent counties voted differently to voters in non-border-adjacent counties. Two, that voters in border-adjacent counties voted differently based on the degree of interdependence between their county and residents on the Mexican side of the border. The evidence suggests that votes for candidate Trump were negatively related to the degree of county interdependence with Mexico.