Cassidy's War Chest Keeps Louisiana Senate Race Competitive Despite Trump Endorsement of Letlow

Rep. Julia Letlow, backed by President Donald Trump's endorsement, holds a narrow lead in Louisiana's three-way Republican Senate primary, but incumbent Sen. Bill Cassidy remains viable for the mid-May runoff. Cassidy has outspent Letlow by more than $9 million on television advertising, undermining expectations that Trump's endorsement would deliver a decisive advantage to Letlow in her first statewide campaign.

Letlow's campaign released an internal poll on April 10, 2026, showing her leading with 29 percent support, followed by State Treasurer John Fleming at nearly 24 percent and Cassidy at nearly 20 percent. The same poll projects Letlow would defeat Cassidy 50 percent to 24 percent in a runoff but shows a statistical dead heat against Fleming in a head-to-head matchup. Cassidy's campaign, combined with the Louisiana Freedom Fund outside group backing him, has spent more than $14 million on advertising, according to AdImpact tracking data, while Letlow's campaign and allied groups have spent $4.6 million. Mike Bayham, a GOP state representative who has not endorsed a candidate, told reporters that "the Trump endorsement has not had a close-out move" and that Cassidy's team "defined her before she introduced herself," referring to early attacks on Letlow's record.

Letlow has focused her advertising almost exclusively on Trump's endorsement rather than attacking opponents. Cassidy's campaign has attacked Letlow over a 2020 video in which she praised diversity, equity and inclusion initiatives during an interview for a University of Louisiana at Monroe position, and over stock trades she made in defense contractors during the Iran conflict. Gov. Jeff Landry, who clashed with Cassidy, endorsed Letlow and made the unusual move of backing a challenger over an incumbent Republican. The Jefferson Parish Republican Executive Committee, one of Louisiana's largest GOP groups, also endorsed Letlow.

Trump's broader political operation has provided limited additional support beyond his initial endorsement. The Make America Healthy Again PAC, aligned with Health Secretary Robert F. Kennedy Jr., pledged $1 million to boost Letlow and oppose Cassidy. MAGA Inc., Trump's super PAC with $300 million in available funds, has not committed spending to the race and has remained silent on its midterm strategy, according to a White House spokesperson who did not respond to requests for comment.

Context

Trump's endorsement carries particular weight in Republican primaries, but its effectiveness varies with candidate profile and spending dynamics. In this race, Cassidy's 2021 vote to convict Trump during his second impeachment trial would typically be disqualifying in a Trump-endorsed primary. However, Cassidy's financial advantage mirrors patterns from previous Senate contests where incumbent war chests have offset challenger momentum. Letlow's low name identification compared to both Cassidy and Fleming compounds the challenge—she has been unable to capitalize on Trump's endorsement to define herself before opponents did so. Fleming, a state treasurer with independent MAGA support, has created a three-way split rather than a two-candidate contest, which dilutes Letlow's potential advantage from Trump's backing.

What's Next

The race will test whether Trump's endorsement power translates to victory when a well-funded incumbent can sustain competitive polling through advertising dominance. Federal Election Commission fundraising reports due next week will reveal Letlow's ability to close the spending gap with Cassidy. The critical moment arrives with the mid-May runoff: if Letlow and Fleming both advance over Cassidy, she faces a general-election-style contest against Fleming that her campaign memo shows as a toss-up, rather than the clear path to victory that Trump's endorsement initially suggested. MAGA Inc.'s decision on whether to deploy resources will determine whether Trump's political operation backs Letlow through a potential runoff.