Former congressman and former South Carolina Gov. Mark Sanford launched a Senate bid on Thursday, becoming the latest high-profile Republican to enter the race for the seat vacated by the late Sen. Lindsey Graham. Sanford, a critic of President Donald Trump, is challenging Darline Graham, who was appointed to fill her brother's term and has secured Trump's "complete and total endorsement."

"We’re at a tipping point, and that’s why I’ve decided to run for the U.S. Senate," Sanford said in a launch video. "I’d ask that you look at my record in Congress and as governor in watching out for your family’s future."

Sanford, who served three terms in the U.S. House in the 1990s, was elected South Carolina governor in 2002 and re-elected four years later. He made a political comeback, winning election to his House seat in 2012 and serving three terms before a longshot presidential nomination challenge against Trump in 2020.

Known as a fiscal conservative, Sanford cited the national debt as a primary motivation for his campaign. "Our country is at a financial tipping point, and I can’t sit on the sidelines while Washington adds a trillion dollars to the debt every 100 days," he stated. "I’m worried for our children because for the first time, America is borrowing from the future faster than we’re building it."

Sanford joins a field that includes Republican Rep. Ralph Norman, who announced his intentions to run this past weekend. Two-term GOP Rep. Russell Fry followed on Monday, and businessman Mark Lynch, who lost to Lindsey Graham in last month's GOP Senate primary, also announced he would seek the nomination.

The special Republican Senate primary is scheduled for August 11, with a runoff election to follow on August 25 if no candidate secures over 50% of the vote.

Representatives Fry and Norman have emphasized their support for President Trump. Fry, a Trump ally, described himself as a "MAGA warrior" and stated, "I will be President Trump’s favorite U.S. Senator, and you will have a MAGA fighter you can count on."

Norman stated, "I'm running to represent the people of South Carolina in the U.S. Senate because we need a fighter who will stand with President Trump and carry on Lindsey Graham’s legacy!" He also expressed a desire to "get the SAVE America Act passed in the Senate."

Norman has received endorsements from conservative Republicans like Sens. Mike Lee of Utah and Rick Scott of Florida, and the political arm of Turning Point USA. Rep. Nancy Mace of South Carolina also endorsed Norman.

Despite the competition, Darline Graham, who met with Trump at the White House before announcing her candidacy, is considered a frontrunner due to Trump's backing and her name recognition. Senate Majority Whip John Barrasso, R-Wyo., has offered his full support to Graham, calling her an "excellent senator."

Senate Majority Leader John Thune, R-S.D., is currently remaining neutral in the race, noting that Graham is a "strong candidate" with a "very accomplished" life, despite lacking elected experience.

Veteran Republican strategist Ryan Williams commented that while the Trump endorsement provides a "major boost," it doesn't guarantee a victory. "Politics is all about timing. You’ve got to seize the opportunity when it presents itself," Williams said. "If you’re an aspiring House member in South Carolina, this is your time to run, regardless of whom the president is supporting."