What do you think about Sen. Barbara Boxer being addressed as "ma'am"
rather than as "Senator" by a U.S. brigadier general during a Senate
hearing? Was this really a breach of protocol?

"Let us not go looking for insults -- or assume stupidity, which it
would be for anyone to insult a senator at a senatorial hearing.

Miss Manners assures you that "ma'am" is, like its masculine
equivalent, "sir," a highly respectful form suitable for addressing
any female, including a president, a monarch and your own mother."