“Maybe the pollsters lied not the people”
Salient point, there, I don’t think many people lie to pollsters. I know it’s kind of promoted here, but, I think most people just refuse to be polled. If they agree to be polled, I don’t think too many lie.
If you’re talking about the exit polls, neither the people nor the pollsters lied, almost certainly.
There’s always a margin of error and it’s possible that the exit poll with only a 4% margin will end up 2,3, or even 4% off.
You can just end up with a bad sample, or the Republicans were too busy to answer the exit poll because they had to go back to their job, and the Democrats had all the time in the world, etc.