"with a very low IQ"

There is a difference between being mentally challenged, and being high IQ but fact challenged. Trump and Dubbya are both probably well above average IQ but are knowledge / fact challenged and value their own opinions over objective reality.

Both are so impressed with their own IQ that they think anything they thought up must be true and don't bother wasting their time with Inconvenient Truths that suggest otherwise.

Remember Dubbya being asked who was the biggest trade partner of the USA, and grinding his impressive mental gears in public to conclude that it must be Mexico because the border was so long that there must be a high volume of goods passing across it? The USA was truly blessed to have such a great mind in the White House. -)

The possibility that Canada or China might do more trade with the USA didn't occur to Dubbya. Saying "I will get back to you" or admitting "I don't know" was beyond Dubbya.