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

John McCain received 243,860 (49%) votes, beating Barack Obama who gained 232,156 (47%) by 11,704 votes in Montana.

John McCain won 43 counties whereas Barack Obama won 13 counties in the total of the 56 counties in the State of Montana.

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 Montana, his 232,156 votes represents 0.3% of his popular vote victory. The remaining 49 states contributed to the remaining 99.7% 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 (Yellowstone, Missoula, Gallatin, Flathead), it becomes very difficult to win majorities in the smaller counties without voter outreach and increased voter participation in them.

Top 15 Counties Comparison in Primary Elections vs General Elections

General Elections
Barack Obama

General Elections
John McCain

Missoula and Gallatin, two of the larger counties, voted in favor of Barack Obama giving him a 17k vote advantage. Yellowstone and Flathead, another larger counties, voted in favor of John McCain giving him a 13k vote advantage. However, John McCain's steady marginal wins in the less popular counties were enough to ocercome that deficit, making him gain an upper hand in the State of Montana.

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