A much greater share of independents — 46% — now say they are either undecided or might change their minds than said so four years ago; in June 2004, only 28% of independents were still wavering. Overall, the so-called swing vote comprises a third of registered voters, up from 21% in 2004 and equal to the swing vote eight years ago. The larger swing vote compared with 2004 is a result of greater Republican uncertainty and undecided independents. Read More

Russell Heimlich  is a former web developer at Pew Research Center.