The March 1 regional SEC primary orchestrated by Georgia's chief election official has reshaped campaign strategy this presidential cycle.

And over the next nine days, the contest combining Georgia, Texas and five other states south of the Mason-Dixon Line in one bloc could decide the wildly unpredictable race for the White House.

Democrat Hillary Clinton hopes to build on her Nevada win by appealing to minority voters in the South, where she’s long held an advantage among black voters in polls. Vermont Sen. Bernie Sanders has stepped up efforts for the same bloc, which is what brought him to Morehouse College in Atlanta last week.

Republican Donald Trump cemented his position as the frontrunner with another dominating victory in South Carolina, giving him a head of steam before the Tuesday caucus in Nevada and the round of votes in Georgia and other states on March 1.

It's shaping up to be a make-or-break moment for Texas Sen. Ted Cruz, who must prove he can unite the conservatives who dominate GOP electorates in the South. Florida Sen. Marco Rubio and Ohio Gov. John Kasich are locked in their own bitter battle to consolidate the mainstream vote.