In other, equally breaking news, I'm also not running for President.
Now the question becomes, what happens to Sarah Palin?
The will she or won't she fueled the media's fascination with her since McCain lost in November 2008. Now that she's out, what does she become?
My guess is that she holds on to her core base of conservative supporters, but beyond that, I think her moment has past.
Liberals won't care about her, and conservatives will look to the likes of Marco Rubio, Chris Christie, Paul Ryan, Scott Walker and Nikki Haley to be their savior in 2016. More immediately, it makes the 2012 race a two-person contest between Romney and whomever (I'm rooting for the not-Romney).
But aside from dodging tough, penetrating questions from Sean Hannity and Greta van Susteren, Palin may lose much of her media oxygen. And then what are we left with? A political supernova who came from nowhere, became one of the most famous politicians in America, a best-selling author and reality star, incredibly wealthy and now ... a letter to talk show host Mark Levin indicating she's not running for President.
So this is how the great political career of Sarah Palin ends (for now?). Not with a bang, not with a bus tour, not with a defeat in the Republican primaries, but with a whimper.
When she wakes up tomorrow morning, she'll probably not wonder "will people still care about me?", because she's never struck me as being particularly introspective. But to answer the question she won't ask, the answer is: yes, for now. And maybe if she endorses someone, for that little period of time. But after that, she'll fade into the relative obscurity she probably does not want.