State Treasurer John Fleming holds a narrow lead in the race for the Republican nomination in Louisiana's U.S. Senate contest, according to a new Emerson College Polling survey.

The poll, conducted in partnership with KLFY News 10 and released Thursday, surveyed 500 likely Republican primary voters from April 24-26, 2026. Fleming garnered 28% support, followed closely by U.S. Rep. Julia Letlow at 27% and incumbent Sen. Bill Cassidy at 21%. An additional 22% remained undecided, with businessman Mark Spencer receiving 2%.

The margin of error stands at plus or minus 4.3%. No candidate reached the 50% threshold needed to avoid a runoff, pointing to a likely June contest between the top two finishers if the election occurred today. "If the Republican Primary for Senate were held tomorrow, the poll indicates the race would move to a June runoff, as no candidate appears to meet the 50% threshold," said Spencer Kimball, executive director of Emerson College Polling.

Fleming led among men with 36% support, compared to Letlow's 27% and Cassidy's 20%. Women showed a tighter split, with Letlow at 27%, Cassidy at 23% and Fleming at 21%. Age breakdowns varied: voters under 40 favored Cassidy at 30%, those in their 40s and 50s split evenly around 24-28%, and those over 60 leaned toward Fleming and Letlow in the low 30s.

Favorable ratings highlighted vulnerabilities for the incumbent. Cassidy drew 30% favorable and 49% unfavorable views, while Letlow had 40% favorable and 31% unfavorable. Fleming scored 42% favorable against 15% unfavorable, with higher neutrality at 36%.

Respondents viewed Letlow as most supportive of former President Trump's agenda at 41%, followed by Fleming at 26% and Cassidy at 21%. The economy topped voter concerns at 43%, with crime at 16%, education at 10%, healthcare at 9%, and immigration at 8%.

The survey used an online panel matched to voter files and weighted by demographics. Louisiana employs a nonpartisan blanket primary system for U.S. Senate races, where all candidates appear on one ballot and the top two advance to a runoff regardless of party. However, this poll targeted likely Republican primary voters.

Cassidy, a senator since 2015, seeks a third term after winning re-election in 2020. Fleming, Louisiana's treasurer since 2024, previously served three terms in the U.S. House from 2009 to 2013 and as USDA undersecretary under Trump. Letlow has represented Louisiana's 5th Congressional District since 2021.

The Emerson poll arrives amid a competitive GOP primary, with challengers positioning against Cassidy's record, including his support for certain infrastructure projects like carbon capture, viewed negatively by 34% of respondents.