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

John McCain received 1,148,015 (59%) votes, beating Barack Obama who gained 781,574 (40%) by 366,441 votes in Louisiana.

John McCain won 54 counties whereas Barack Obama won 10 counties in the total of the 64 counties in the State of Louisiana.

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 Louisiana, his 781,574 votes represents 1.1% of his popular vote victory. The remaining 49 states contributed to the remaining 98.9% 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 (East Baton Rouge, Jefferson, Orleans, St. Tammany), it is still possible for other candidates to catch up, given the amount of large counties of similar size.

Top 15 Counties Comparison in Primary Elections vs General Elections

General Elections
Barack Obama

General Elections
John McCain

East Baton Rouge, Orleans and Caddo, three of the larger counties, voted in favor of Barack Obama giving him a 95k vote advantage. Jefferson, St. Tammany and Lafayette, another larger counties, voted in favor of John McCain giving him a 136k vote advantage. However, John McCain's steady marginal wins in the less popular counties were enough to maintain that lead, making him gain an upper hand in the State of Louisiana.

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