On 'Likely Voters': Did screening for likely voters lead to accurate polling?

President Obama, campaigning in Colorado on Nov. 1, 2012. In the weeks prior to the presidential election, I wrote of the rather formidable gap between how President Obama fared in polls where respondents were classified as "likely voters" and how he performed in polls where all registered voters were included. At the time, I went back to data from the 2004 and 2008 presidential...