It’s not racist if you use a racial or ethnic slur in respect to yourself, right?
As far as saltine language goes it can sound a little Ritzy.
Just like no-one can object if I call myself queer. Doesn’t give them permission to do so.
I think it is racist, but it’s a kind of racist not many people are going to complain about.
Unless, of course, you’re doing it to trivialize racial slurs in general.
My son went through a phase recently where he would ask nonsensical questions in the form, “Daddy, are you a (something) ?”. He asked me at various times if I was a table, an apple, and a towel. One day he asked, " Daddy, are you a cracker?" I had to give that some thought before I answered.
Mike Birbiglia has a funny bit about trying to start a trend of white guys calling each other cracka.
Anyway, as to the OP, something tells me you’re not really looking for serious discussion, so whatever. Call yourself what you want.
But Mike Birbiglia is a damned funny guy. Go look him up on YouTube.
Cracka, please!
For future reference, OP, you don’t need the clause “as a white guy.” We could figure that out from the content of your post.
Hi my name is Graham, Graham Cracker.
I read in an old Georgia public school history text (1960s) that Georgia cattlemen used to drive their cattle to market to sell them. They would crack their whips over the cattle to drive them ahead, and that is where the term Georgia Cracker came from.
The same text said most slaves were treated quite well.
The term is not necessarily a slur. Some Florida Crackers take pride in the term.
Are you an actual Cracker, or just white? Who are you using it to? Other whites, or blacks? Why are you using it?
If you’re not an actual Cracker in the original sense, if you use it to non-Cracker whites, they’ll think you’re just crazy.
You’re an animal, Cracker.
True, but it’s well to have that extra level of explicitness. Without it, there would be more room for confusion and mistaken assumptions.
A black guy asking if he could call himself a cracker would be a far more interesting question.
I often call Indians ‘wogs’, so if you want to call white people ‘crackers’ go right ahead.
What’s your ethnicity? Because wog can be pretty damn offensive.
True but in the USA the word wog would generally be greeted with a 
If you call yourself queer, you’re downright strange.
(Mind you, if it makes you gay, go right ahead. Say every fortnight or so. It costs nothing, so it’s not too dear.)
Cracka what!
50+ years ago in Atlanta it wouldn’t have been a problem. The pre-Braves minor league team was the Atlanta Crackers. (The article gives an alternate origin of the term “cracker”.)
The Negro League team was the Atlanta Black Crackers.
But let me tell you, the phrase “white cracker”, when uttered by an African-American, is definitely not a positive. It’s like calling someone a <bleep> head.
I would avoid the term.