Because this is what is called to be a master at pitching snake's oil.

What "pathological lying"? He is no more lying than the average politician, and maybe less.

What about his statements on the crowd sizes? He also said Mexico was going to pay for the wall and that doesn't look like it will happen at all.

"alternative facts" ;). At least those err, factual inaccuracies didn't have anything to do with formal government policy.

As for the wall, he's making steps to that at least; whether they'll work on a practical matter is of course something else. Can't accuse him from not following up on his promises, anyway.

He said he will impose a tax on Mexican imports and use the proceeds to pay for the wall - That sounds on track.

A 20% import tariff was floated, but was fairly quickly walked back after a cold reception from the Texas GOP delegation and strong opposition from the Texas Association of Business (Texas does a lot of import/export business with Mexico). Now they're looking into unspecified other mechanisms.

You understand that the tax will be passed on to US consumers via higher prices right?

You understand that this is no rule of nature, right?

It's not like Mexico is the only source of some goods. Or that they can't make concessions (and assume the extra hit on their own margins) if their sales drop. Or tens of other factors and outcomes.

I do understand that, however it seems unlikely at the moment that they will choose that option.

Well, it's not making Mexicans pay for it, but Americans.

As for his other promises, I'm also not sure how he's going to manage to massively increase the defense forces while basically halving taxes.