I agree, Dave. I was saying to someone last week that at this stage in the events, politicians are basically salesmen. You want your 'product' to sell better than its competitors, so you emphasise its strongest points, avoid wherever possible its disadvantages and limitations and if you know a weakness of your opposition's product, you may well drop it in to build up the advantages of yours.

This is, in part, why most politicians are suboptimal. The skill they need to do the job - rational thought, careful consideration of options, detailed study of what a proposed law means in practice - are almost directly opposed to what they need to do to get the job (saying what you think in convincing and blow the consequences.)

So yes, that is the norm for all politicians. But Trump and Johnson go far beyond that because they are quite willing to claim benefits for their product that they know are simply not there. The honest salesman restricts themselves to what the product can do while showing it in the best possible light, the dishonest one doesn't care as long as they get the sale.