There was pressure to ignore warnings because President Reagan was scheduled to be present for the launch.
In higher levels of management, things get more political. Looking good and getting exposure count for a lot. No one wants to be the guy that made nasa look bad by slipping the launch date.
In tech, most managers tend to be rated by how well their projects meet schedules and how much operating expense they can minimize, since that's the only thing their managers have any sense of control over. Your boss doesn't want to take the heat for delaying project "glitter unicorn" by a week so you can fix 2 major security holes in the service, one which allows customers to login without a password. And this is why your company won't spend $500 for a data backup system or why it takes 4 months to get your broken keyboard replaced.
It's turtles all the way up.
I can totally see this - I mean, in my job management generates major stress for everyone to get a trivial product update shipped on time. Imagine the pressure to get a space launch to 'launch' on time. Makes our system seem like General Mao's. But better of course.
I was wrong--he wasn't going be attend, but there (allegedly) were plans to have a televised conversation between him and Christa McAuliffe during his State of the Union address that night.
However this may not be true. While trying to find an e-source, I read that there were some politically-motivated rumors that the white house ordered the shuttle to launch for this reason. Feynman investigated that rumor and didn't find any evidence that the white house ordered the launch.
It's possible the detail about an on-air tv conversation between the president and a schoolteacher astronaut could have been fabricated as well to make Reagan look bad, or it could have been based on elements of truth. For example she was expected to broadcast 2 lessons to students from space, so the capability definitely existed. It doesn't seem too far out that they would have liked for this conversation to happen during the State of the Union, though that doesn't mean the white house ordered the launch.
I read this in Edward Tufte's essay Visual and Statistical Thinking (http://www.edwardtufte.com/tufte/books_textb), which discusses how better information displays might have convinced NASA management to postpone the launch.
It also appears as a chapter in his book Visual Explanations.
I didn't have any luck finding sources on the internet (lots of keyword overlap). Tufte is much better informed than pretty much all of us, though it's possible he printed what amounts to an unsubstantiated rumor. FWIW he also served on the Columbia accident investigation board.
I think there were other pressures to launch as well. The launch date had been postponed 3 times already for various reasons. Cynical danek: I wouldn't be too surprised if some manager's performance review was based on how many launches took place on the scheduled date.
