From an article in the San Franciso Chronicle:
“In the latest twist, Sen. Barbara Boxer, D-Greenbrae, is caught in the public furor… The California senator sponsored legislation in 2000 to restore the tribe’s federal status.”

My understanding is that the convention is to write the senator’s name, then D for Democrat or R for Republican, and then whom they represent. Furthermore, while someone from California elected to the US Senate would be a Californian senator, she would not be a California senator but a US senator. So is the Chronicle claiming that Boxer is a state senator representing Greenbrae?
It does seem to be a mistake; IIRC the AP style guide has you indicate the senator’s state. However, it may be that you can list their actual home town if it’s the senator for the state the newspaper is in.
I’d say it’s an error, but it might not be a style error. You’re correct, Ryan; Sen. Boxer represents California, not any given city or district thereof. It might be that the paper’s style is to refer to senators from California by their home district or where they have their office, but regardless of what the style guides say, that is inaccurate reporting.
–Cliffy
That’s usually how you’d list a STATE Senator, I think. I suppose it’s beyond obvious to the readers in California that that’s the state she represents, but I can’t recall ever seeing that done before.
The custom I’ve seen in journalism ranging from the New York Times to the Podunk Weekly Gazette (well, not really that, but would the Pulaski Democrat or the Queen Central News of Camden NY be acceptable substitutes?) is that the first use of a U.S. Senator’s name is followed by a one-letter abbreviation of his party affiliation, a comma or dash, and the state he represents, abbreviated if over five letters, e.g., Edward Kennedy (D-Mass.) or Hilary Rodham Clinton (D, N.Y.). The same styling is used for House members, even though most of them represent a district within a state, the idea being that Tom DeLay being a Republican from Texas matters more than that he happens to represent Texas’s Fifth District (if I have that correct).
State representatives, in either house, are customarily followed by D or R and the numerical district, the idea being that it should be clear from context what state it is they represent, although I suppose an article about the annual meeting of the National Association of State Legislators would have to adopt a differing style.
What TheRyan picked up on is a relic of a far older system, predating the one-man-one-vote decisions, where a legislator is referenced by his/her party and home town, so that my state’s senators would be John Edwards (D., Raleigh) and Elizabeth Dole (R., Salisbury). It’s not in error per se, but it’s “a blast from the past” in terms of usage, about equivalent to using a nominative absolute in contemporary writing.
It’s appropriate in a local paper to refer to members of the U.S. House from that state by their district, because that is who elected them, although national news stories will refer to them by state.
–Cliffy
Yes, the Chronicle is in California, and yes, their whole readership knows who Barbara Boxer is, but calling a U.S. Senator “D-Greenbrae” is idiocy. If the Comical feels it absolutely necessary to point out that the senator is from Greenbrae, this is how you do it: “…Sen. Barbara Boxer (D-Calif.) is… Boxer, a Greenbrae resident, sponsored…”