It's always a risk, but Roberts appears to be a very low risk for turning lib once named to SCOTUS. I think the prez has chosen well.
Instead we get a guy that Charles Krauthammer believe won't vote to overturn Roe, meaning he would be NOT originalist:
It is almost impossible to imagine Roberts doing something as grand as that. He would not have the audacity. My guess? He upholds Roe, purely for reasons of precedent. And very quietly.