US President Donald Trump and Health Secretary Robert F. Kennedy Jnr succeeded in their efforts to defeat Senator Bill Cassidy in Louisiana’s Republican primary, a signal of the enduring strength of the president’s hold on his party despite an unpopular war and soaring fuel prices. Cassidy was one of seven Republican senators in 2021 who voted to convict Trump on the charge of inciting an insurrection on January 6 that year. He placed last in a three-way race on Saturday against Representative...