President Barack Obama won Oregon by 17 points in 2008 and is leading by nearly double digits in 2012, but his campaign is running commercials in the Portland, Oregon media market to blunt the potential impact of Libertarian Party nominee Gary Johnson, whose candidacy could siphon pro-marijuana voters from Obama and make the state race a lot closer than expected. 

After noticing a report on the Gay Patriot blog, the Washington Examiner's Michael Barone wrote on Tuesday he believed the Obama campaign was running commercials in Oregon because so many Oregonians favor the legalization of marijuana, which is one of Johnson's signature issues: 

My guess: someone in the Obama campaign somewhere are concerned that Libertarian party nominee Gary Johnson may cut into Obama’s vote in Oregon, which could make Mitt Romney competitive as George W. Bush was in 2000. After 2000 many left-leaning voters were wary of third party candidates like Nader, for fear that votes for them would elect a Republican. But Johnson differs from Nader in one important way: the former governor of New Mexico favors liberalizing the laws against marijuana.

“Is the Obama campaign afraid they’ll desert to Gary Johnson?,” Barone asks. 

Obama leads by 8.5 points in the RCP Average of the polls in Oregon. Kerry won the state by only four points in 2004, and Al Gore barely beat George W. Bush in 2000 (47.0% to 46.5%) because Green Party candidate Ralph Nader received five percent of the vote. As Barone noted, Johnson may take more from Obama than Nader did from Gore because of his liberal views on marijuana legalization.

Barone also makes these observations. In "two of the last three presidential elections Republicans got 47% of the vote and, when a left-wing third party candidate got 5% of the vote, the Republican candidate almost carried its 7 electoral votes." In 2010, "Democrat John Kitzhaber won the governorship by only a 49%-48% margin, Republicans won a 60-60 tie in the state House and Democrats held on to only a 16-14 margin in the state Senate." And in the 2010 House elections, Oregon Democrats beat Republicans by five points, gaining 51% of the votes to 46% for Republicans.

Karl Rove also has said Oregon could be in play for Republicans in the future.