By Wednesday, just hours after Trump’s successful revenge campaign in Indiana unseated a majority of Republican state senators who had blocked his gerrymander there, the pressure in Columbia had become palpable.

Trump’s political muscle flexing in Indiana is already reshaping the landscape in red Southeastern states, where GOP lawmakers who had been reluctant to revisit redistricting are now facing an unmistakable ultimatum. David McIntosh, president of the Trump-aligned Club for Growth, whose PAC poured $2 million into the Indiana races, framed the message bluntly. “The voters in Indiana signaled that Republican primary voters want their leaders to be aggressive on this,” he said. “They want them to move quickly, get the job done wherever it’s possible.”

The biggest pressure point is in South Carolina, where Massey had previously thrown cold water on the idea of a redraw ahead of the state’s June 9 primaries. Trump called Massey both on Monday and Tuesday, before Indiana’s results were in, according to a person familiar with the calls who was granted anonymity to discuss them. Massey did not respond to multiple calls and texts seeking comment.

While it remains unclear whether the legislature will ultimately adopt a new map that erases the seat of lone Democratic Rep. Jim Clyburn, GOP lawmakers who had expressed hesitations are now moving toward support, a significant shift from just days ago. The Indiana results have effectively served as a live-fire demonstration of what can happen to those who defy the president on redistricting.

McIntosh said it is too early to say whether the Club for Growth would primary any hesitant lawmakers, noting that if primaries go forward without new maps, it could take two years before some state legislators face voters again. But he added a pointed warning for those still wavering. “The leadership in South Carolina, they saw the results in Indiana,” McIntosh said.

South Carolina is not alone in feeling the heat. Across the South, Republican state lawmakers who had hoped to delay redistricting until after the midterms are now recalibrating, aware that Trump’s political operation has both the appetite and the resources to make examples of those who stand in the way. The message from Indiana, as one strategist put it, was a very clear warning: fall in line or face the consequences at the ballot box.