Probably an illegal
If it isn't that it is something equally significant.
People don't drop out of a nomination at this stage unless there is something they do not want to come out in the confirmation process.
She claims she was born in Texas.
But bogus claims are a nickle a cart load.
Obama claims he was born in the USA too.
“Probably an illegal”
My guess is that during the vetting process some “stuff” popped up. So, she was quietly “asked” to withdraw.