He sort of gets some of it.
There are many debates among economists about how to resurrect the subpar, so-called recovery and generate some serious new job creation. But there is also widespread agreement that nations cannot tax their way into prosperity,
devalue their way into prosperity,
Depends on how you define prosperity. Japan sort of did it this way. Not ideal, due to suboptimal real terms of trade, etc., but that’s they way they set up their system. And as soon as they stop devaluing their currency (buying dollars) they have problems. Europe is in the same bind.
spend their way into prosperity,
This is wrong. The output must be sold, either to the public sector or the private sector. That’s a political choice- public goods or private goods.
or pursue trade-limiting protectionism as a path to prosperity.
This can also work, but as above, is suboptimal in general. And, it is vital when it comes to strategic materials and intellectual knowledge. For example, military needs are best sourced domestically to assure a supply in times of war, etc.
All of this is weakness.
I’d say in general yes, all of his argument displays a weakness of understanding.