In some Democratic circles the notion is quickly dismissed. But Obama’s expected nomination opens up the possibility that ’08 could be the year that Democrats secure some beachheads in the south, the region most African Americans call home. For an update on Democratic prospects in the south, check out Louis Jacobson’s largely skeptical Stateline.org post “Will Obama have coattails in the South?” (flagged by Facing South‘s Chris Kromm). Among Jacobson’s more encouraging observations:

On a statewide level, the biggest down-ballot impact for Democrats will likely come in the close race for North Carolina open-seat governorship, which pits Lt. Gov. Beverly Perdue (D) and Charlotte Mayor Pat McCrory (R). Even before the presidential primaries began, incumbent Democrats seemed to be well-positioned to retain several other statewide posts in the Tarheel State, including attorney general and secretary of state.
…When North Carolina Democratic chairman Jerry Meek endorsed Sen. Obama the day after the North Carolina primary, he said, “I cited my belief that he would have a substantial down-ballot effect. It will be strongest in statewide races, and all of those are intensely competitive.”
Only three of every four people who voted for president in North Carolina’s Democratic primary also voted in lower contests, such as the labor commissioner race. Still, the total Democratic turnout was three times as high as the Republican turnout, so one can expect that many of the new voters will have an impact in the fall as well, said John Davis, president of the North Carolina Forum for Research and Economic Education, a business and political research group. “Obama’s impact down-ballot will be huge for Democrats, if he is able to sustain his momentum,” Davis said.

On the Senate:

Two U.S. Senate seats — those held by Republicans Roger Wicker of Mississippi and Elizabeth Dole of North Carolina — are far more threatened by former Mississippi Gov. Ronnie Musgrove (D) and North Carolina state Sen. Kay Hagan (D) than had been predicted just a few months ago. And endangered U.S. Sen. Mary Landrieu (D-La.) may find an energized black base her only way to win a third term given the state’s population loss following Hurricane Katrina.

Jacobson has a lot to say about possible conservative backlash, that Obama will actually increase the GOP vote. That’s a question mark, based on the debatable assumption that previously apolitical reactionaries will turn out to vote against Obama. What appears to be a sure bet, on the other hand, is a record-level Black turnout in the South — a major asset for down ballot Dems.