Ideology and interests in congressional voting: The politics of abortion in the U.S. Senate

Many studies suggest that personal ideology accounts for much more of congressional voting behavior than does attention to the desires of the electorate. There are two main explanations given for this seemingly robust conclusion: 1) poor measures of constituency preferences compared to those for ideology or behavior, and 2) representatives “shirk” on an inattentive electorate. We argue that existing studies have been biased against the “interest” explanation by ignoring the structure of American Congressional elections, in particular the party primary process. Correcting for the party primary effect, we show, within the context of abortion politics, that constituency interests possess greater explanatory power than previous models would suggest.