5 reasons why Trump won the South Carolina GOP primary

While some Republicans griped that Haley was seeking to court independents and Democrats in addition to GOP voters, South Carolina's open primary system allowed for such a campaign.

Even with that system in place, Trump still won the Republican primary because he won overwhelmingly with — guess who? — Republican voters.

Republicans made up roughly 68% of the GOP primary electorate, and Trump won them 70% to 30% over Haley, according to exit polling conducted by Edison Research for the National Election Pool.

One of the most interesting phenomenons of Trump's victories in the Iowa caucuses and the South Carolina primary is the former president's enduring support with evangelical Christians.

In South Carolina, where evangelicals have long held immense sway in local GOP politics, they were all in for Trump this year, giving him 71% of their votes, compared to 29% for Haley.

And evangelicals made up well over a majority — 61% — of the primary electorate, per Edison Research.

In recent years, there have been widening disparities in candidate support and the income levels of voters, with working-class voters increasingly shifting toward conservative Republicans, while upper-income voters have continued to embrace center-right Republicans while also becoming more receptive to Democrats.

Trump performed strongly with voters with making under $50,000 (72% to 27%) and between $50,000 and $99,999 (61% to 39%).

And Haley nearly beat out Trump (49% to 50%) with voters making over $100,000.

Despite Haley's appeal to voters to embrace GOP candidates of a new generation, Trump still won every age demographic in the South Carolina primary, per Edison Research.

The former president's best-performing age group? Voters aged 17-29, who backed him over Haley 65% to 33%.

In South Carolina, seventeen-year-olds can vote in primaries if they turn 18 by the general election.

In the South Carolina primary, Haley won voters in urban jurisdictions by 11 points (57% to 42%).

But they only made up 8% of the GOP primary electorate.

On the other hand, Trump easily won among suburban voters (61% to 39%) and rural voters (64% to 35%).

Suburban voters comprised 70% of the primary electorate, while rural voters comprised 21% of primary voters.

According to Pew Research, Trump struggled with suburban voters overall in the 2020 general election, with President Joe Biden winning this group by 11 points (54% to 43%).

In recent years, many of the voters moving to South Carolina's suburban communities have shifted those areas to the right, so the state's primary results may not reflect a larger trend regarding suburban voters.

Still, both Trump and Biden will seek to win over this critical voting bloc in November.