Largely because he's made such a stink about not releasing it. Yes, he's concerned (at least) with it "looking bad" or "giving ammunition" to his critics — but that makes it sound like it's even more important for him to do so.
And, to look at it from a different perspective, Romney turned over 23 years of tax records to McCain when the latter was considering Romney as a VP candidate — why would the public warrant only one year? And, of course, there's the example of his father, who sums it up perfectly below. #ddtb
Reshared post from +Think Progress
Mitt Romney has released just one year of his taxes. When his father ran for president in 1968 he released 12 years of his taxes, stating "One year could be a fluke, perhaps done for show."
If you think it's time for Romney to come clean and release 12 years of returns, sign this petition: http://thkpr.gs/zSYGEK
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Tell Romney to Come Clean
This is what we've learned about Mitt Romney from just one year of his tax returns. His father released 12 years of his taxes when he ran for president in 1968, stating "One year could be a f…