NEW ALBANY, Ind. --Senator Barack Obama has had several opportunities to seal the deal and wrap up the Democratic nomination, so why can't he close out this race?Obama lost Pennsylvania by 10 points after the toughest few weeks of the campaign marked by questions about his pastor, his patriotism, his choice of friends and his choice of words, all culminating in an unimpressive debate last week. But he only lost a net 16 delegates Tuesday night and still leads Hillary Clinton by a wide margin in all of the statistical categories. He's now trying to get his groove back in the friendlier political climate of neighboring Indiana. The rallying cry of "yes, we can" on a Southeastern Indiana University's college campus has to be music to the ears of a candidate told by 55 percent of the Democratic voters in Pennsylvania, no, you can't. "We didn't lose by 20, which is where we started. We were able to close that margin to deliver a message that's been consistent throughout, which is, we've got to change how Washington works," Obama said. Obama is still leading Clinton in every statistical category and doing a bit better among his toughest voting blocs. But Pennsylvania turned things into an air of anxious uncertainty. "I think that we only have a few more contests left. One way or another, by June 3, we'll know where we stand. And I think that if we got more states, more delegates, more popular vote, more support, higher in the national polls, doing better in matchups with John McCain in the general election, I think super delegates will select me to be the nominee," said Obama. Clinton says the tide has turned and that as people hear more from Obama, they have more doubts about him and his electability. "I think the fact is that we have been able to create the kind of campaign that I think people haven't seen in a generation," Obama responded. "So we're confident that, as long as we keep on delivering our message and deal with the negative attacks launched by Senator Clinton's campaign, we'll end up being successful. We are going to have a great debate here in Indiana." Now the spotlight is on Indiana, a more hospitable state, as Obama tries again to win a big one and reignite the calls for Clinton to get out. "We campaign in every state and we work hard in every state," Obama said. "Senator Obama, I'm sure, it feels good to be back in the Midwest and campaigning in terrain that's very much like the areas that he represents as the senator from Illinois," said campaign manager David Axelrod. So much of the campaign is about geography and demographics. States closer to you tend to know you better and like you more. States with a lot of elderly, working-class white men and women tend to prefer Clinton. Where the population is a bit more educated, more affluent, they tend to favor Obama. Indiana is like a small Pennsylvania but not quite as much in terms of the blue-collar factor. And it is close to Illinois. It's coming down to a question of who is the best candidate against John McCain in the fall. Obama does tend on balance to come out a bit ahead of Clinton on that one. Voters in Indiana and North Carolina will go to the polls on May 6 to vote in the Democratic presidential primaries. There are 84 delegates up for grabs in Indiana. There are 134 in North Carolina. The presumptive Republican nominee was on the campaign trail Tuesday. Senator McCain was in Inez, Kentucky, holding a town hall meeting. That state's primary will be held on May 20. Among the topics to discuss there were wasteful spending in Washington, securing the nation's borders and the economy. "American families are hurting. Tonight a family will be sitting around the kitchen table trying to figure out how to keep their home, make their payments, which have jumped through no fault of their own, how they're going to afford health care," McCain said. The North Carolina GOP is refusing a request by Senator McCain to not run a TV ad that focuses on Obama's former pastor. That commercial calls Obama too extreme for North Carolina, and McCain says there is no place for that kind of campaigning.