In a prime-time address, Trump alleged major election-related interference by China.

President Donald Trump, in a primetime speech Thursday night, alleged vulnerabilities exist in American election systems, despite declassified documents released by his administration largely discussing vulnerabilities that have been known for years and that election officials around the country have tried to address.

Donald Trump had grand designs for America’s 250th anniversary. A sprawling state fair on the National Mall. Military flyovers galore. The most powerful fireworks display known to man. And, most important, a primetime speech from the president himself ...