Former South Carolina governor and congressman Mark Sanford has entered the Republican Senate primary to replace the late Lindsey Graham, adding a prominent Trump critic to a field already led by the President’s endorsed candidate. His decision means Trump’s backing has not prevented other high-profile Republicans from contesting the nomination, potentially making the race more competitive and exposing divisions within the party.

Sanford announced his campaign on Thursday, saying the country was at a “tipping point” and that this motivated his decision to run. He previously served as South Carolina’s governor and in Congress, and has been an outspoken critic of Donald Trump; the article identifies him as the latest notable Republican to join the contest for Graham’s former seat.