Abstract We study the informational effectiveness of electoral campaigns. Voters may not think about all political issues and have incomplete information with regard to political positions of candidates. Nevertheless, we show that if candidates are allowed to microtarget voters with messages then election outcomes are as if voters have full awareness of political issues and complete information about candidate's political positions. Political competition is paramount for overcoming the voter's limited awareness of political issues but unnecessary for overcoming just uncertainty about candidates' political positions. Our positive results break down if microtargeting is not allowed or voters lack political reasoning abilities. ...