Why are John McCain and Hillary Clinton advising California voters?

I just received a letter from Arizona Republican Senator John McCain urging me to vote for California proposition 77. This message was paid for by Governor Schwarzenegger's California Recovery Team. Last week, I received a "special message" from New York Democratic Senator Hillary Clinton urging me to vote no on proposition 75. This message was paid for by the California Democratic Party.

Maybe I should be happy: 1 Republican senator and 1 Democratic senator wrote to give me advice.

I'm more concerned about why these senators from out-of-state think it's in their best interest to give advice to California voters on their issues at home.

[[Originally, I posted my opinions on these propositions - I think that detracts from my primary message/concern, and so I've removed that here]]