From my analysis below, especially on simple math about taxation and the nature of democracy, it seems Martin Ford is wrong.

Suppose that the production of almost everything (clothes, furniture, etc.) and most services is automated to the degree that the process itself costs almost nothing, but still requires raw materials to produce. The scarce factors would be raw materials, energy, and key human resources (product designers, system engineers, roboticists, venture capitalists, etc.). (There will remain certain services that are not automated, but these require only a small fraction of the population to provide.) The main earners would be those key people and the owners of raw materials and energy resources. We can suppose they make up a small fraction of the population. These people will earn huge income and can afford many luxuries of life. Some portions of their income will be taxed and distributed to the mass.

Since much of the production and distribution costs will be eliminated, more and better products/services can be provided. Let's say four times more or better than in the current world. Even though the rest of the population receive only a fraction (say 25%) of the income through governmental distributive scheme, this could be equal to the total amount that the current production creates. In a democratic country, political pressure will mount to distribute enough income for everyone to be fairly satisfied with their material well-being and something like 25% is a rate that the riches will likely accept. Since the riches will comprise a small fraction of the population, they will be pampered in a lot of ways, not unlike in the current world. The key difference is that the middle class and the poor will become one and the same since the jobs of most current middle-class would have been automated away. (We are talking about the economic aspect, there might still be differences among these two classes based on education, family background, for example).

Overall, this would be a world where say 5% of the population designs, analyses, manages, and faciliates automation, 10% provides services that are not yet replaced by automation, 3% owns raw materials, 2% governs, and the rest lives pretty well-off at least for non-competitive products. The 80% might not get to own beach-front properties or products designed exactly to their personal tastes (which require work from good designers), but they will live materially better than most of us now. How they choose to spend free time would be an interesting issue to explore. I am optimistic though that the world where most people are free to pursue their own interests without needing to work on things they don't enjoy will be a better world. I’d love to see this actually happening sooner than later.

In conclusion, if the automation is significant enough to put the majority of the population out of work, it will also likely create such a large surplus that people will be materially better off through reasonable tax rates on the productive workers and capital owners. A caveat that might ruin this utopian scenario is in the case we and supercomputers in the future cannot find a way to live sustainably given the raw materials and energy resources we have access to from this earth (or other planets).