Do non-citizens affect US Congressional elections?

U.S. citizens against immigration argue that immigrants commit voter fraud and skew election outcomes towards progressive candidates. These arguments have increased in number and severity since the Supreme Court ruled in 2013 that states cannot require photo identification from voters. We examine whether the size of the non-citizen population is related to election outcomes. Previous research indicates that non-citizens sway elections in favour of progressive candidates but only in elections where the victory margin is small. We find no evidence of a relationship between non-citizens and vote outcomes. We find evidence that the percent of the population that is non-white is positively related to percent of votes cast for democratic candidates.