Here's an interesting article on selling Obama to the Republicans who feel disenfranchised by McCain. The author, a former lifetime and Goldwater Republican, has some good bullet points, and they are fleshed
out in detail in his article. I'll give you the short version:
1) Don't waste time on Democratic cornerstone issues like health care, education, and jobs. Republicans have other priorities.
2) Don't bash Bush. He's not in this election.
3) Do not try to change Republican sensibilities against higher taxes.
4)Obama was cosponser of a bill in the Illinois State Senate that resulted in the largest tax cut in state history. McCain was highly critical of Bush's tax cuts before flipping and supporting them.
5) Despite their rhetoric, the last five Republican presidents have grown government spending considerably, resulting in large deficits. Much of this is due to untrackable pork. Obama has passed legislation to make government spending public and transparent, resulting in this website.
6) Obama is the one that has engaged free market, nongovernmental solutions to problems personally. McCain's wealth comes entirely from the public trough and his heiress wife.
7) McCain defends the intrusive and unconstitutional expansion of executive power that has occurred over the last 8 years.
8) Obama is more willing to attack Al Quaeda wherever they are, whereas McCain is going to continue the policy of leaving them safe in places like Pakistan.
9) McCain, the child of privledge, and having a father who was an admiral, still only finished 894th out of 899 cadets at Annapolis. Obama, the rugged individual, came from a home on food stamps and earned academic scholarships to Harvard, and graduated Magna Cum Laude.
It will be interesting to see how much crossover there is. It is also interesting to see that the Republican party has drifted so far from its conservative roots (as embodied by Jefferson, not Robertson) that a Democrat could actually outscore them on their issues.