Believe it or not there is a science of lies. The science basically says we all lie all the time to someone. Brains just don't work the way you might suppose.
Here is what we know by the science you can confirm for yourself:
Big lies work for politicians because they allow them to divide people into believers and non-believers. The lie itself may have just a bit of truth to it. Historically, every democracy that falls into dictatorship falls into it through such big lies. If you are on the 'good' side you accept it and can test if someone is not on your side if they protest.
This has been used for a long time.
Even Plato described it. He pointed out that democracies inevitably fail into dictatorships. A person comes along and divides the people with a lie and promises greater efficiency and reason.
NEVER VOTE FOR A DIVISIVE LIAR.
That said, even good cults use big lies for exactly such testing for members of the good cult. Here is how Physics does it.
Also divisive. But not pernicious.
Geo. Washington explained, in 1797. We have always been in this age of big lies. It is not an age. It is every age.
We know how to fix it. Physics keeps the crazy lying truthful by only trusting their math not their words. The US Constitution is a study in dividing power. By this they controlled any one person's inevitable grab of power to be limited.
Your only and best defense is to NEVER VOTE FOR A DIVISIVE LIAR. History and science says you will be sorry.