*ahem* The NASA and Morton-Thiokol engineers refused to sign off on the launch.
They were overridden by NASA and M-T management.
I can't help but think the final decision was driven by the desire to have the Shuttle in orbit for that evening's State of the Union address.
Yes, I believe that's absolutely correct. I also remember something about Rockwell engineers also expressing some serious concern about the weather conditions with respect to ice and it's effect on the seals.
You are correct to point out and to clarify that it was both NASA and Morton-Thiokol management that insisted that the launch go forward. As to the pressure that felt because of the State of the Union, I'll leave to others to decide. But, I think it's fair to say that the Roger's Commission was equally tough on both NASA and MT's management.