Polls said Reagan would lose. In his race against Carter, they said he would lose, then moved it to too close to call. When he won by ten, the media said all the movement was over a weekend, a physical impossibility.
Ignore them.
I remember that election well as it was the first one I was old enough to vote in. From Labor Day on, it was pretty obvious that there was a real groundswell for Reagan. Even in liberal Massachusetts, I remember seeing Reagan signs everywhere. Reagan would go on to win Massachusetts (and just about every other state).
But yes, I also remember the networks having the race as a nailbiter right to the very end in order to keep their boy Carter in contention. Then when Carter was blown out of the water, it was attributed to a sudden "weekend surge" to Reagan. Laughable. The race was over by Labor Day.