How likely are we in the US to build a new electrical distribution grid?

There are two parts to this questions. The basic technical issue is that it is impossible to transfer power generated in the western part of the US to the east coast (and vice versa) - the physical distance is simply too great.

So if there is a desire to erect large wind or solar-photovoltaic production facilities in the west (or Great Plains) and move that power to either coast, then it is going to be necessary that a major investments be made in high voltage DC transmission (which is not limited by physical distance) to move that power.

The other half of the problem is political - is there sufficient political will to make that investment - both in financial and environmental terms? My guess is that the answer to that one is no. Historically, this country has never taken decisions to boldly move ahead to do something that clearly makes sense, preferring instead to adopt only minimal, incremental improvements, and then only when faced with imminent crisis. Sorry to be cynical, but that's the way its always been and, in spite of the optimism of new leadership, I don't see that changing any time soon.

Why would it be 'futile'? We can implement any form of generation, anywhere in the nation, and plug it into the existing grid easily. Upgrading the grid is a real need too, and can be done independently of the production side.