As recent state polls across the country indicate a tightening of the presidential race in favor of John McCain, a new Rasmussen poll of 700 likely Minnesota voters finds support for Obama at its lowest margin to date across nine polls conducted by the survey organization since February 2008. The Illinois Senator is also enduring his lowest favorability rating in the state, while McCain’s numbers are on the rise.

The Rasmussen poll, conducted August 13th, gives Obama a 46 to 42 percent lead over McCain. Obama has led McCain in all nine Rasmussen surveys released over the past seven months, but 46 percent is a low water mark for Obama – down from 53 percent in May, to 52 percent in June and early July, to 49 percent in late July. Obama’s lead over McCain has subsequently decreased from a double-digit margin in five straight polls to just 4 points in the new August poll.

McCain, meanwhile, eclipsed the 40 percent mark for just the third time in Rasmussen’s on-going matchup surveys. In other good news for McCain, his favorability rating has climbed to 60 percent – rising steadily from 52 percent in May, to 54 percent in June, to 56 percent in early July, to 57 percent in late July.

Obama, meanwhile, has seen his favorability rating drop to 56 percent – its lowest mark ever as measured by Rasmussen, falling precipitously from 65 percent in early July to 60 percent in late July.