Trump Allies Warn of Primary Challenges for GOP Senators

A pro-Trump social media influencer sparked attention with a viral post suggesting that Arizona Republican Kari Lake could challenge Sen. Joni Ernst (R-IA) in 2026. The post stemmed from Ernst’s perceived hesitation to support Pete Hegseth’s nomination for Secretary of Defense.

“Kari Lake was born and raised in Iowa,” Rogan O’Handley wrote. “What if she returns home to primary Joni Ernst in 2026 and take her Senate seat?”

Charlie Kirk, who played a key role alongside Elon Musk in Trump’s battleground state get-out-the-vote efforts, also criticized Ernst over Hegseth. “People in Iowa have a well-funded primary challenger ready against her,” Kirk wrote on X (formerly Twitter). “Her political career is in serious jeopardy.”

Donald Trump Jr. joined the criticism, stating, “If you’re a GOP Senator who voted for Lloyd Austin but criticize Pete Hegseth, then maybe you’re in the wrong political party!”

Trump pollster John McLaughlin underscored the former president’s influence over Republican voters. “Republicans are totally behind his agenda and are totally supportive of him putting the right people in place so he can solve the country’s problems,” McLaughlin told RealClearPolitics. “If certain Republican senators side with the Democrats, they do so at their own peril.”

Meanwhile, Axios reported that Trump allies are closely watching Sen. Bill Cassidy (R-LA), who is set to chair the Senate Health, Education, Labor, and Pensions Committee, as he handles Robert F. Kennedy Jr.’s nomination for Secretary of Health and Human Services. Cassidy, who voted to convict Trump in his second impeachment trial, could face a primary challenge from Rep. Clay Higgins (R-LA).

Amid this political maneuvering, former Rep. Matt Gaetz of Florida has withdrawn from consideration for Attorney General, while Pete Hegseth continues to meet with GOP senators to salvage his embattled nomination. Other nominees, such as former Democrats RFK Jr. and Tulsi Gabbard, and pro-union Labor Secretary nominee Rep. Lori Chavez-DeRemer (R-OR), are still awaiting Senate review.

There are rumors that Trump might consider recess appointments to install his Cabinet quickly, but pursuing primary challenges against dissenting Republican senators is a more conventional political strategy.

However, history shows primary challenges can be fraught with difficulties. For example, Sen. Lisa Murkowski (R-AK) survived a conservative primary challenge during the Tea Party era, winning reelection as a write-in candidate. Sen. Susan Collins (R-ME) remains one of the few Republicans capable of winning statewide in Maine. Meanwhile, Sen. Mitch McConnell (R-KY), who recently stepped down from leadership, may not run again.

These three senators—Murkowski, Collins, and McConnell—are widely seen as the least reliable votes for Trump’s nominees and broader agenda.

While Trump-endorsed candidates struggled in the 2022 midterms, costing Republicans the Senate, his influence proved decisive in the 2024 presidential election, sweeping all seven battleground states. Nevertheless, Republican Senate candidates fell short in Michigan, Wisconsin, Arizona, and Nevada, despite Trump’s victories in those states. Kari Lake, a potential challenger to Ernst, has lost Senate and gubernatorial races in the past two cycles.

Historically, poorly chosen GOP primary candidates have delayed Republican Senate majorities. In the 2010 red wave, Republicans picked up 63 House seats but failed to capture the Senate, only gaining the majority in 2014 after more competitive candidates emerged.

Still, Trump has successfully nudged some Senate critics out of Washington, such as former Sens. Jeff Flake (R-AZ) and Bob Corker (R-TN), and retiring Sen. Mitt Romney (R-UT). Many Never Trumpers have left the Republican Party altogether over the years.

With Republicans set to retake control of the Senate on January 3, just 17 days before Trump begins his second term, there is pressure on the former president to achieve significant results quickly. While some allies advocate for aggressive tactics to ensure his nominees are confirmed, others warn against the risks of intraparty division heading into the 2026 midterms.