If you read the entire article on Politifact you will see that while they acknowledge her statement on borders, it is not simply about open immigration.
In a brief speech excerpt from 2013, she called for "a hemispheric common market, with open trade and open borders, some time in the future with energy that is as green and sustainable." Clinton has said she was talking about clean energy, but we can’t fully evaluate her remarks to a bank because we don’t have the full speech.
We rate this statement Mostly False.