Robert O’Brien was Catholic and joined the Church in his 20s. The Deseret News calls him the “highest ranking” member of the Church in the U.S. government.
As many readers know, Ezra Taft Benson was the Sect. of Agriculture in the 1950s. And there have been many Latter-day Saints in a myriad of other federal government positions.
O’Brien is close to Mitt Romney but unlike Romney is unique in praising Trump’s presidency. Some people call him a foreign policy “realist,” and other say he will be a hawk just like John Bolton, whom he replaced.
You can read more about O’Brien here.
Here is an analysis of O’Brien’s hawkish foreign policy philosophy.