Julia Letlow beat John Fleming 56.8% to 43.2% in Louisiana's Republican Senate runoff on Saturday 27 June, a 13.6-point margin far wider than late polling had suggested 1. The runoff had been set for 27 June after Senator Bill Cassidy finished third in the primary . A mid-June Rigamer survey had shown Letlow's 15-point lead collapse to two points ; the result buried that reading. Turnout fell 21% from the May primary, to 316,538 ballots 2.
The money ran almost entirely one way. The Accountability Project Inc, a super PAC aligned with Governor Jeff Landry, reported $5.9m in independent expenditures against Fleming; Trump's own Securing American Greatness super PAC added $1m 3. Super PACs can spend unlimited sums on a race but are barred from coordinating with the candidate they support. Fleming drew essentially no outside support. Jamie Davis took the Democratic nomination 80-20 and advances to the general election.
Set the result against Texas. There a nine-to-one spending advantage for John Cornyn collapsed because Trump had endorsed Ken Paxton, who won by 28 points . In Louisiana the endorsement and the money pointed the same way, and Fleming lost by more than 13 points. Across the cycle's two Senate primaries a Trump endorsement has predicted the winner better than cash has in either direction.
Two contests make a pattern, not a law, and this one cannot separate the endorsement from the spending. What Louisiana shows cleanly is money amplifying an endorsement it agrees with, rather than substituting for one.
