“He didn’t.”
Hasn’t this been brought up in court on more than one occasion? Doesn’t that mean lawyers had to get involved?
Yes, and yes. But the question was, why has he spent millions to prevent its release. Not the same thing.
The "millions" birthers cite are the total legal bills paid to a law firm which handles legal matters for the campaign. It wasn't money all spent on birther lawsuits. So wrong on point 1.
The lawyers never filed a suit seeking to prevent release of the document. All they did was file the automatic motion to dismiss in response to other people's suits. So wrong on point 2.
Answer: He didn't.