The current high spirits in the campaign could be tempered in coming weeks when West Virginia and Kentucky voters render their verdict on the Democratic race.
And it's not just thatis heavily favored to win both states - but more than that they could further underline Obama's lackluster support in Appalachia, a region that is ground zero for the sort of populist Reagan Democrats both parties will covet in the fall.
As Clinton noted this week, Obama's lagging vote totals among white, working class voters in broad swaths of culturally conservative territory continue to feed doubts about his ability to expand his electoral base in Appalachia - a region which, according to one's definition, can stretch from the cornfields of western New York all the way through the deltas of northern Mississippi.
That's territory that includes states - Ohio, Pennsylvania, Virginia and West Virginia - that will be key to a Democratic victory in November. And some Democrats are already worried thatis poised to scoop up crucial votes in the region if Obama is the Democratic nominee.
"McCain's going to camp on the Pennsylvania-Ohio border" in Appalachian regions, said Democratic strategist Dave "Mudcat" Saunders, of Roanoke, Va. "He knows if he wins those states he can't lose."
Obama has consistently come up short in Appalachia, even when he was romping to victory nearby. Consider Obama's 14-point victory in North Carolina on Tuesday, when he still soundly lost a series of counties near the Tennessee border, including Cherokee, Clay and Graham.
Clinton's strong performance in the Appalachian region's 11th Congressional District caused Rep. Heath Shuler, a North Carolina superdelegate, to throw his support behind the New York senator's flagging campaign.
Virginia, another strong Obama primary state, also delivered the majority of its rural Appalachian votes to Clinton. In the Feb. 5 contest, Clinton overwhelmingly won a series of counties nestled in the state's southwest corner between West Virginia, Tennessee and North Carolina.
The numbers were similar in Ohio on March 4. Except for Cincinnati-based Hamilton County, every county along the Ohio River went for Clinton, often by over 70 percent. The Appalachian portion of Pennsylvania was equally strong for Clinton when she won statewide on April 22. Washington, Greene and Fayette counties, each along the Ohio or West Virginia state lines, each gave at least 71 percent of its vote to Clinton.
Democratic strategists chalk up Obama's problems in the region to several factors. His race, many say privately, is clearly an obstacle in the predominately white region, as is an elitist image both the Clinton and McCain camps have worked hard to stamp him with.
But Obama's Appalachian struggles do not faze supporters such as Rep. Rick Boucher (D-Va.), even though Clinton won his district by an almost 2-to-1 margin.
Boucher suggested voters in his largely rural southwest Virginia district would ultimately gravitate to Obama's message of economic development, telemedicine to expand health care, federal support for water infrastructure projects, and broadband development to provide expanded Internet service and attract high tech jobs.
"It's a challenging region for Democratic presidential candidates under all circumstances," Boucher said. "But I am absolutely confident that he will be even stronger than Sen. Clinton was in contending for the votes of rural voters."
In the general election, "I do not anticipate a defection of Democratic voters away from Sen. Obama and to the Republicans," Boucher sid. "Sen. Obama has special qualities that will enable him to be more competitive" than previous Democratic nominees Al Gore and John F. Kerry, both of whom came up short in Boucher's 9th District and statewide.
Democratic strategist Saunders, who worked for former North Carolina Sen. John Edwards' presidential campaigns and helped propel Democrat Mark Warner into the Virginia governor's mansion, said emphasis on issues over rhetorical style would be key for Obama.
"What people don't understand about Appalachia is that we've heard all this 'hope' and 'change' stuff since the English kicked the Scotch-Irish out in the 1700s. We're 'hoped' out. Nothing ever changes out here. He's got to come with some solid policies."
Rep. Nick J. Rahall, the longtime Democratic congressman from southern West Virginia, said Obama was a lot closer to Appalachia voters than might be apparent on the surface. After all, sections of central and southern Illinois bear a striking resemblance to much of Appalachia.
"Sen. Obama is from a coal state. Sen. Obama is for using coal in an environmentally sound manner. Sen. Obama's familiar with these technologies," Rahall said.
Moreover, the prolonged Democratic primary fight with Clinton has made rural voters more comfortable with Obama, Rahall said. That was on display in the Indiana primary this week, which Obama lost by a narrower margin than many had expected, and in which he kept down Clinton's vote totals in some Ohio River counties.
"With each succeeding primary election, as Sen. Obama becomes more toughened, he will continue to improve," Rahall said. Locals will "recognize that he is more attached to their issues than John McBush - I mean McCain."
Questions over what factor Obama's race will play in Appalachian voters' decisions were brought into stark relief this week with Clinton's comments about "white Americans" backing her over Obama. It's a highly sensitive issue that is difficult to measure in polls and surveys, but also a reality Obama clearly must address.
"The South has changed a lot, but not that much," Gary Pearce, a Democratic consultant in Raleigh, N.C., said of his state and surrounding areas.
But racial questions can be mitigated.
"The way he can change things is to increase the electorate - attract young people and independents," Pearce said.
North Carolina, considered a safe Republican state in November, will be a good test of Obama's message.
"There are some Democrats that think instead of getting 42 percent [about the average vote totals of Bill Clinton in 1992 and 1996, Gore in 2000 and Kerry in 2004], he can get 47 percent," Pearce said. "Four years from now, a lot of people think this could be a battleground state, with a rapidly growing, highly educated, more professional" populace.
Phillip J. Ardoin, political science professor at Appalachian State University in Boone, N.C., said Obama's party affiliation, much more than his race, may be his undoing in parts of Appalachia.
"Religion plays a big role in this area of the state among white voters, and I am constantly surprised how many white social conservative voters continue to believe only the Republican Party can represent the interests of 'Christians,'" Ardoin said. "The e-mails going around which question Obama's religious views and patriotism have been popular and, I think, effective."
And perhaps most daunting for Obama, not all of the concerns comes from expected quarters. Some Democrats who have backed Clinton in the primaries may very well give the Republicans another look, said Mary Ann Kominar of Kermit, W.Va. - the wife of 14-year state Del. K. Steven Komnar. Both are Clinton supporters.
"I have to support my party. I don't ever intend to let my party down. But a lot of people are saying 'McCain looks better every day,'" said Kominar, who lives in Mingo County, W.Va., just across the Kentucky state line.
"I'm opposed to Obama because of his religious beliefs. I believe Rev. [Jeremiah] Wright told me a whole lot," Kominar said, echoing familiar Republican talking points. "The fact that [Obama] doesn't pledge allegiance to the flag, he doesn't wear a flag pin, concern me."
Obama simply isn't the right kind of Democrat for the region and would lose in West Virginia just as former party standard-bearers Gore and Kerry did, she said.
"I think over the years they've tried to force some very liberal New Englanders down our throat - Obama's not from New England, but he still fits that mold."
By David Mark