He never didn’t support amnesty.
True.
Until the end of July 2015 he supported deportations only for the criminals. Everybody else he was for a legalization amnesty without deportation based on merit.
Then at the end of July 2015, he switch to a touchback legalization amnesty where everybody would be deported, but the good ones would be expedited back for a legalization amnesty.
Beyond a legalization amnesty, his last stated position on a citizenship amnesty was that he would not be for it now but he would consider it later.