A head to head comparison of the 2008 Nebraska General Election gives us an idea of the break down of the voters.    

John McCain received 452,979 (57%) votes, beating Barack Obama who gained 333,319 (42%) by 119,660 votes in Nebraska.

John McCain won 89 counties whereas Barack Obama won 4 counties in the total of the 93 counties in the State of Nebraska.

Presidential General Elections

During the 2008 General elections, over 131M total number of votes were cast. Barack Obama got 69,448,278 (69.4 Million) over John McCain's 61,739,059 (61.7 Million). He won the popular vote by 7,709,219 (7.7 Million). Even though he lost to John McCain in the State of Nebraska, his 333,319 votes represents 0.5% of his popular vote victory. The remaining 49 states contributed to the remaining 99.5% popular votes victory.

Top 15 Counties in Primary Elections vs General Elections

All Candidates (General Elections)

These 15 counties play an important role in these Primary elections. If a candidate, can get a sizable majority in the largest counties (Douglas, Lancaster, Sarpy), it becomes very difficult to win majorities in the smaller counties without voter outreach and increased voter participation in them. However, steady win margins in less popular counties can amount the marginal win to win the entire State. (As in the case of John McCain in the State of Nebraska).

Top 15 Counties Comparison in Primary Elections vs General Elections

General Elections
Barack Obama

General Elections
John McCain

Douglas and Lancaster, two of the larger counties, voted in favor of Barack Obama giving him a 16k vote advantage. Sarpy, another larger county, voted in favor of John McCain giving him a 10k vote advantage. However, John McCain's steady marginal wins in the less popular counties (like Buffalo, Hall, Lincoln and more) were enough to overcome that deficit, making him gain an upper hand in the State of Nebraska.

Related References: 2016 Nebraska Primary Election Story, 2016 Nebraska General Election Story, 2020 Nebraska Primary Election Story, 2020 Nebraska General Election Story, 2012 Nebraska General Election Story