Common predictions of motivated political reasoning assume that biased voters should polarize after exposure to mixed arguments. However, despite extensive evidence of biased information processing, evidence of attitude polarization is surprisingly rare. This study contributes to explaining this apparent puzzle by showing that Bayesian voters can simultaneously evaluate information in line with predictions of motivated reasoning and moderate pre-existing attitudes. Experimental evidence from four studies concerning highly salient political issues in the US and the UK confirms that exposure to a balanced set of arguments leads to depolarization of attitudes, despite the presence of a confirmation bias in the evaluation of evidence. Contrary to common predictions, moderation of attitudes occurs especially among those with strong prior attitudes and those with high levels of political sophistication. By showing that even biased voters can moderate their attitudes in response to evidence, this study casts a positive light on the consequences of motivated political reasoning, and indicates that information can actually smooth the extreme fringes of the electorate during intense political campaigns.