Sen. Bill Cassidy lost Saturday’s Louisiana Republican primary according to a race call by the Associated Press.

Cassidy, who served two terms in the Senate, was one of seven Republican senators who voted to convict President Trump after the January 6th insurrection at the Capitol. That vote put him at odds with Trump and his MAGA coalition, ultimately leading Trump to push Rep. Julia Letlow to run against Cassidy.

Cassidy’s bid for a third term was viewed as a test of Trump’s grip on the party–and of what voters want from their representatives in Washington. The primary pitted Cassidy, a veteran lawmaker, former physician and chair of the powerful Senate health committee, against Letlow, a political newcomer and a millennial MAGA loyalist.

A former college administrator, Letlow won a special election in 2021 for the House seat her late husband, Luke, was set to assume before he died from COVID in 2020.

In Congress, Letlow sponsored a bill to collect oral histories from the pandemic and has focused on education and children. She introduced the “Parents Bill of Rights Act,” which would allow parents to review classroom materials like library books and require schools to notify parents if their child requests different pronouns, locker rooms or sports teams.

She also serves on the powerful appropriations committee and has embraced Trump’s agenda.

Letlow, who came first in Saturday’s primary, will face Louisiana state Treasurer John Fleming in the runoff on June 27. Cassidy came in third.

The election result is a victory for President Trump who has put Republican loyalty to the test on the ballot so far this year in Indiana state senate primaries and in Cassidy’s race.

Another major test of Trump’s influence comes in Kentucky’s primary on Tuesday when Republican Rep. Thomas Massie, who has found himself at odds with the president, faces a challenger endorsed by Trump.