They find that exposure to the news resulted in greater Democratic candidate support, independent of the editorial leanings of the newspaper. News exposure also likely increased voter turnout. From their abstract:
We find no effect of either paper on political knowledge, stated opinions or turnout in post-election survey and voter data. However, receiving either paper led to more support for the Democratic candidate, suggesting that media slant mattered less in this case than media exposure. Some evidence also suggests that receiving either paper led to increased 2006 voter turnout.Read the article.