South Carolina voters will choose the Republican candidate in the race to replace the late Sen. Lindsey Graham. The Trump administration plans the largest mass visa revocation in history. And how Penn State students reacted to a massive drug bust that made national headlines. Here’s what you need to know today. South Carolina offers the next big test of Trump’s influence. President Donald Trump helps Senator Darline Graham off the stage during a campaign rally in Myrtle Beach, South Carolina, on August 21. Saul Loeb/AFP via Getty Images President Donald Trump quickly endorsed Senator Darline Graham when she announced her candidacy to run for a full term following the sudden death of her late brother, Senator Lindsey Graham. But his candidacy has faced skepticism, particularly after a misstep in a debate last week. Now, the president’s influence faces its next test this election season. Today’s Republican Senate runoff in South Carolina between Graham and Rep. Ralph Norman will show whether Trump’s support remains a major factor in the Republican races. Norman is a staunch conservative who has described Graham as the “establishment’s” choice, and some Trump supporters are wary of Graham’s lack of experience. Trump’s influence also faces a test in Oklahoma’s Republican gubernatorial primary. State Attorney General Gentner Drummond has boasted of his closeness to the president, even though Trump endorsed his opponent, former state Sen. Mike Mazzei. Trump has since criticized Drummond as a “fake Republican.” Oklahoma’s race has become particularly brutal and personal. Fights between the two candidates over allegations about their fitness for office led to the two men releasing drug tests in recent days. Here are the other primary races to watch. NBC News Chief Data Analyst Steve Kornacki takes a closer look at a potentially swing district in South Carolina in The Data Dive, a new subscriber-only newsletter on the numbers, trends and data shaping the biggest stories heading into the midterm elections. Read today’s edition here. More politics news: The Supreme Court handed an early victory to the Trump administration in its effort to implement an executive order aimed at limiting who can receive mail-in ballots ahead of the midterm elections. For subscribers: During the election campaign, Trump branded himself the “fertilization president” and promised to make IVF free. What happened? Bessent threatens new sanctions on Iran following ‘economic D-Day’ threat 00:39 Bessent pressures countries to cut economic ties with Iran 00:0000:00 The United States took steps aimed at further isolating Iran after Treasury Secretary Scott Bessent threatened an “economic D-Day” against the Islamic Republic. Bessent said yesterday that his department is sanctioning nearly 60 corporations, individuals and vessels that he says enable the Iranian regime’s “recklessness.” Bessent said Trump has been making phone calls to world leaders asking them to stop trading with the Iranian regime. Earlier yesterday, the United Arab Emirates said it will end all trade relations with Iran. While Iranian leaders downplayed the threat, experts said the success of Bessent’s announcement will depend on whether the country’s most powerful trading partners – China, India and Russia – decide that the US threats are credible. Read more about the reaction to Bessent’s announcement. “Everything is on the table” in terms of retaliation. US prepares for mass visa revocation The State Department is expected to announce in the coming weeks the revocation of business and tourist visas issued between 2016 and 2026 whose holders have applied for asylum or are now seeking asylum, according to State Department documents obtained by the Associated Press and two US officials. The measure to revoke so-called B1 visas – which are generally used for business trips – and B2 visas – which are generally issued for tourism, family visits or medical care – could affect up to 200,000 foreigners and would be the largest mass visa revocation in US history. The revocations would not necessarily result in the immediate deportation of their holders, and would likely face legal challenges. Here’s what else you should know. Staff election: Penn State’s reaction to an alleged drug ring The Old Main building at Penn State University in State College, Pennsylvania. Islam Daghestani / iStockPhoto via Getty Images archive When prosecutors announced that 14 people had been charged in what authorities described as a highly profitable cocaine trafficking ring centered on two Penn State fraternities, the allegations quickly made national headlines and became the target of online discussion. But when I went to State College, Pennsylvania, to see how the news resonated on campus, I found something unexpected: Students hardly seemed to care. For two days, I knocked on fraternity and sorority doors and spoke to students about the alleged plan. Of those who stopped to chat, most said they did not know the defendants, had not heard of the alleged operation before the arrests or did not believe it was that important. My story captures the striking disconnect between the severity of the allegations and the decidedly muted reaction on campus, even as it has endured years of national scrutiny and scandals involving Greek life. —Matt Lavietes, Breaking News ReporterRead all about itNearly two weeks after powerful storms hit the Midwest, thousands of people in Gary, Indiana, are still waiting for the power to come back on. San Francisco 49ers owner Jed York pleaded no contest to two misdemeanor charges after his arrest in Ohio. Former child actress Raquel Lee Bolleau alleged in a lawsuit that a Disney employee sexually assaulted her while filming a Disney Channel movie in 2001. For subscribers: Ukraine sanctioned the creators and distributors of the Russian children’s cartoon “Masha and the Bear,” calling the show pro-Kremlin propaganda that threatens its national security. For subscribers: Google and Samsung unveiled their new foldable phones, and Apple is expected to join the market soon. Here’s how the phones compare to each other and to traditional smartphones. Selected by NBC: Online Shopping, Shopping Made Easy Shoppers say this wheeled duffel bag holds seven days of clothes and lasts a decade. It costs less than $50 today. Plus, Baggu’s summer sale is almost over and the NBC Selected team is picking out their favorites before they sell out, including items with adorable Hello Kitty prints and the brand’s popular crescent-shaped bag. Sign up to The Selection newsletter for actionable product reviews, expert shopping tips, and a look at each week’s best deals and sales.