The main goal of this paper is to analyze the political outcome in countries where the relevant issue in elections is the control of immigration. In particular we explore the consequences on the political outcome of the fact that parties are either ideological or opportunistic with respect to this issue. In order to do that we use a simple two-party political competition model in which the issues over which parties take positions are the level of border enforcement and the way it has to be financed. We show that an ideological rather than a pure opportunistic behavior gives parties an advantage to win the election. In particular, in most of the cases we consider we find that rightist parties have an advantage to win in countries where the relevant issue in election is illegal immigration. This result may help us to understand the recent success of anti-immigrant and rightist parties in several countries.