Polls: Late Oregon numbers split on whether race is tightening there; Obama surges nationally

Here are the results of four different polls from Oregon that were taken between May 14 and May 18. Two of them indicate a fairly dramatic closing of the gap by Hillary Clinton; two of them do not. (Click on the image to see a larger version of Pollster‘s tracking chart for Oregon.)

• American Research Group (5/14 – 15): Obama 50, Clinton 45
• SurveyUSA (5/16 – 18): Obama 55, Clinton 42
• Public Policy Polling (5/17 – 18): Obama 58, Clinton 39
• Suffolk (5/17 – 18): Obama 45, Clinton 41

If the surveys indicating a fairly close race prove to be correct, it will lend some rhetorical firepower to the Clinton campaign and afford her a few more bargaining chips as she negotiates the terms of her eventual exit. Even so, it would be unlikely to re-start the Hillary bandwagon in media or fundraising circles.

More: A national Gallup poll released yesterday gave Obama his biggest lead over Clinton to date at 55-39. And today a Gallup analyst writes that Clinton seems to be slipping with her core constituencies:

“The broadening of Obama’s appeal for the nomination seen in Gallup’s May 16-18 polling is fairly widespread, with the percentage favoring him increasing among most demographic categories of Democratic voters. However, as a result, certain groups that were already highly supportive of Obama for the nomination — men, 18- to 29-year-olds, postgrads, and upper-income Democrats — are now overwhelmingly in his camp. Obama is currently favored among these groups by a 2-to-1 margin, or better, over Clinton. At the same time, support for Clinton among some of her traditionally stalwart support groups — women, Easterners, whites, adults with no college education, and Hispanics — has fallen below 50 percent.”