GOP battle brewing in coveted South Carolina

(CNN) -- The GOP presidential hopefuls have their eyes set on South Carolina, which hosts the South's first party nominee contest Saturday.

After former Massachusetts Gov. Mitt Romney's win in Michigan, the race for the party's nomination is wide open.

South Carolina is potentially a big symbolic win for Republican candidates. The state's Republican party has sided with the eventual presidential nominee in every election since 1980.

The state, once part of the old Democrats' "Solid South," has become a Republican stronghold -- voting Republican in 10 of the last 11 presidential elections.

The GOP holds the governorship, both U.S. Senate seats, four of the state's six U.S. House seats and both houses of the state legislature.

A week after the Republicans, Democrats will hold their race -- and African-American voters are expected to play a key role in that primary. Recent polls show Democratic Sens. Hillary Clinton and Barack Obama vying for their party's top spot.

The Palmetto State has an open primary, meaning registered voters can participate in either primary.

In the 2000 GOP primary, one of every three voters was a self-described member of the religious right. These voters helped hand George W. Bush the win over John McCain, and could also play a key role in this year's critical contest. Watch how candidates are competing in the Palmetto State »

Veterans also make up a significant portion of South Carolina's GOP electorate. In 2000, they made up 27 percent of voters in the Republican primary. Watch what tactics candidates are using in South Carolina »

In the last contest, McCain won several counties along the coast, thanks to the sizeable population of veterans and national security voters there. The areas have since swelled with retirees, many from out of state.

Region by region

The northwest portion of South Carolina, known as the Piedmont Region, represents the state's staunchest Republican area. Greenville County is the most populous and most industrialized county in the state. The religious, conservative area also includes Spartanburg and Anderson.

The Midlands includes Columbia, the state capital, and much of the black majority 6th Congressional District. It's the most Democratic part of the state and also includes Orangeburg, home of the historically black South Carolina State University.

The Pee Dee region was originally home to the Pee Dee Indians. It has its commercial roots in tobacco and cotton. The city of Sumter has become more progressive and tends to be slightly more Democratic than the rest of the state.

The Low Country region is a diverse group of counties that collectively mirror the statewide vote. There is a significant black population, especially in central-city Charleston.

Charleston and new, prosperous recreational communities along the coast are giving Republicans more strength. E-mail to a friend

CNN's Robert Yoon and Alan Silverleib contributed to this report.

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