WASHINGTON — After the political convention confetti is swept away, a more sobering tradition of the presidential election begins: The regular, top-secret intelligence briefings for the nominees.

President Harry S. Truman started the briefings to get candidates up to speed before they take office.

If Hillary Clinton is the Democratic nominee, much of the information will sound familiar. She read high-level intelligence reports when she was secretary of state. Her critics, however, note that the FBI is investigating whether her use of a private server in her home to send and receive work-related emails — including 22 that have since been classified — broke any laws.

On the Republican side, Donald Trump’s loose-lipped campaign remarks have left some intelligence officials worried about whether he can keep the nation’s secrets.