Zogby Polls released these results on July 6: Obama 44%, McCain 38%, Barr 6%, other and undecided 12%.
Recent Rasmussen Polls only list Obama and McCain, but the latest Rasmussen Poll showed a 5% lead for Obama over McCain. It is unfortunate that the presidential polls don’t list all 6 candidates who will be on the ballot in states containing a majority of electoral votes.
The last poll that seems to have asked voters to choose from four candidates was this CNN poll, released July 2. It shows Nader at 6% and Barr at 3%.