Ronald Reagan was supposed to give a state of the union address a couple days after the launch. He wanted to use the success of the space program as part of that speech. While there was no direct order, it's clear that NASA management felt significant political pressure to push the launch forward or risk reduced funding from congress. It's clear they screwed up, just wanted to add some context to the climate when they made these decisions.
This comment needs more upvotes. The political pressure on NASA is extreme. The only people doted over more than the astronauts were the politicians. Look into the origins of the Triana satellite and its subsequent fate for a particularly ridiculous example.
