UPDATE: John McCain poked fun at fellow senator Barbara Boxer on “Hannity” Thursday.
“Thank you for calling me ‘Senator’ and not ‘sir,” McCain said to the host, grinning.
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Yesterday at an EPW hearing, Sen. Barbara Boxer (D-Calif.) asserted herself. A military officer testifying began to respond to one of her questions by calling her ma’am. But Boxer interrupted: “Do me a favor,” she said, “could you say ‘senator’ instead of ‘ma’am?’ It’s just a thing, I worked so hard to get that title, so I’d appreciate it, yes, thank you.”
Fox News actually reported out this story by calling up an Army spokesman to ask if it was disrespectful for the officer to call Boxer ma’am. Their conclusion: no big deal! What do you think
Winwomenspeak's Weblog 
SENATOR BOXER:
WHAT AN EGO TRIP. “SENATOR” AND NOT “MA’AM”. THAT REALLY SHOWS YOUR TRUE VALUES – “I AM AN IMPORTANT SENATOR AND I LIKE TO HAVE EVERYONE REMEMBER THAT FIRST AND FOREMOST.” THE APPROPRIATE RSPONSE IN THE MILITART IS “SIR” AND “MA’AM”. GET USED TO IT EGOMANIAC.
I dont think its a big deal to call a senator “Sir” or “Ma’am”. According to protocol, it is correct. It is better for a Senator, who is obviously very much senior to an Army Brigadier General in protocol, to be the bigger person, and not harp on petty trivialities like how she would like to be addressed.